You can't expect a "self found" character to be as strong as a trading character
We don't, and have very specifically mentioned this so as to ward off fallacious bullshit like yours. Didn't seem to work.
Self-found play should be reasonably viable within the premises of the game. It isn't really, because almost every long-term goal in this game is gated behind a gear check that can't possibly be met without heavy trading. You simply don't find good enough items yourself to do more than the most basic, shallow things like completing the campaign on merciless, reaching level 80 and things like that. Any more is pretty literally impossible without trading. There's nothing wrong with trading being more effective, but there's definitely something wrong with it being absolutely required in order to scratch the surface of the game.
- PoE drops level appropriate gear. D3 dropped gear BELOW your level, meaning trading would always be better than anything you found.
That's just completely incorrect. Isn't PoE the game where 95% of unique drops are under level 30? In D3, the game is hardcoded to not drop items too far below your level. This was the case even at launch, although that threshold was further raised in a later patch. PoE doesn't drop things with an ilvl below that of the zone, but it can drop item types of any level. I'm not even remotely hyperbolic when I say that nearly every unique one finds is low-level trash, to the point where there are entire weekends where I don't find a unique above level 50. The ilvl doesn't matter there, nor does it for cruel-difficulty items dropped in merciless and maps.
- PoE's skills scale off gem levels, passives and random prefix/suffixes. D3's skills mainly scaled off the item level dependent DPS of your weapon, meaning anything you could buy would be miles better than what you have.
This has nothing to do with the fact that good items are way, waaaaay too rare in PoE.
- PoE's endgame content can be performed with decidedly mediocre gear, it will just be slower. D3 had giant gear check walls on its endgame content. At one point in D3 it was pretty much impossible for certain classes to progress in Inferno without buying a weapon from someone that was further progressed.
PoE's endgame is pretty undefined. Some seem to think any maps at all count as endgame, others feel that it's only really maplvl 72+ or thereabouts. One is most definitely barred from the real endgame, i.e. the higher map levels, as it's completely impossible to build up any serious amount of them without trading. The currency investment that goes into high-level mapping (and, consequently, reaching level 90+) is immense and in no way sustainable with drops. More importantly, clear speed with self-found gear is unbearably slow after maplvl 70ish, to the point where it's almost an exercise in futility at times. Certain bosses and even just elites can take minutes to kill, not because they're difficult mobs but because their defensive stats clearly aren't tuned for the kind of DPS that can be achieved without artificially inflating your gear via trading.
- PoE's trading is a big time sink, due to the lack of an automated AH and universal currency. D3's trading was damn near instant.
Is this some kind of argument for anything? Yeah, PoE's trading facilities are an utter joke, which is ridiculous because the gameplay mandates so much trading.
Good loot is just excessively rare in this game and it completely destroys self-found longevity because you very much will end up farming for weeks and weeks without ever finding anything worthwhile. This makes the gameplay completely pointless and unrewarding while at the same time doing nothing to actually make trading appealing other than it being the only way to "get anywhere" in PoE. This is PRECISELY the problem D3 had in the beginning. Like, an exact replica of the issue.
If PoE had strong multiplayer gameplay and convenient trading facilities, it would have been a completely different story, but I'm sure you would have to agree that neither is the case. Every game has a effort vs. reward curve, and PoE's is so far off the mark that it boggles the mind. They've made the process of finding your own gear so miserable and prohibitive that it's beyond any possible dispute that they intend for everyone to trade in order to unlock access to the parts of the game that are worth playing. They've gone so far as to officially state that they do not want to support self-found play in any way, yet simultaneously neglect to make the game's multiplayer gameplay or trading facilities any good at all. In fact, both are so poor that many want to play self-found precisely because the multiplayer and trading is so utterly terrible in this game.
I just hate how people insist on responding to this as if the desire to play self-found is some kind of overly entitled, unreasonable request, or make baseless claims that the game is perfectly fine when played that way when in reality it is deeply, fundamentally flawed and borderline broken. This is a genre where solo play is a common choice, it's not as if I'm asking for viable self-found play in World of Warcraft or something. The multiplayer facilities are nowhere near good enough to justify snubbing solo play as bluntly as GGG have, and it's doubly stupid when they have not only suggested in the past that they wanted to cater to every venue of play but also have the means to effortlessly do so with their woefully underutilized league system. It's very much as if they simply dislike players who like anything outside the mainstream format and refuse to do anything for us out of principle. This also goes for the cutthroat league, for instance, and whatever else people have been requesting for two years now. Wasn't this supposed to be the custom league ARPG?
If ever there was a game where it would be natural to cater to less mainstream preferences, it seems that PoE should have been it, but they've completely dropped the ball on their promises of providing this, not just with regard to solo play but anything that would fit within the league structure that they've so woefully failed to provide. They promised all kinds of things and then, two years later, have provided only a few very underwhelming league formats that nobody has ever requested while constantly ignoring every single thing that people do request in that regard. I'm pretty sure not one single person has ever suggested things like the Anarchy league etc., but where is any of the stuff for which there is actually a widespread demand?