I also agree with Neversink. They're trying to do the right idea, but the implementation is off or not broadcast correctly. There's also significant changes that are probably following what they're doing that most people don't have the foresight to understand. Basically what they wanted was the "less loot, but better loot" idea, but they implemented the first half and not the second half... yet.
If you're unfamiliar with how it works, "smart loot" is much more complicated than regular loot currently. EVERYONE wants smart loot. The problem is smart loot has to be pre-calculated before dropping which is why you see it in instances like specialized chests, ritual, and Grand Heist rewards. Those items were there before any IIQ or IIR calculations took place and they were generated when the zone was. Other loot is just a billion RNG rolls hitting once a mob dies and the IIR and IIQ checks hit.
What's the solution to allow more smart loot? Less items overall. Well, as you can see, they can't do that without the outrage. EVEN IF they had told people they were doing this, probably even if they mentioned the smart loot changes to follow, the pre-league launch would've been a shitshow and launch numbers would have been appalling because of sheep mentality. So what was to be the "item squash" to prepare for bigger and smarter loot changes in the future has basically been fucked. Reddit is probably shooting itself in the foot because this almost certainly means that they're going to keep throwing MORE items instead of BETTER items out to keep the smoothbrains happy. Reddit is PoE's greatest Hero and Villain.
Another thing that's interesting is GGG launches stuff sometimes in an underwhelming state. This may sound like a bad idea, and Mathil had a great take that if you're playing day 1 and your friend couldn't and he asks "should I play?" and you say "Yeah, but probably in a week." That person probably isn't coming back in a week. This is pretty much true, but there's a side to this that I think most MOBA/Battle Royale players know about that the ARPG community doesn't, or at least PoE's.
EVERY OTHER GAME RELEASES NEW CONTENT OVER TUNED TO HELL AND AS A PRE-SET META, THEN HAS TO NERF IT TO HELL. They give you immense power then almost IMMEDIATELY have to take it away. Apex Legends, Overwatch, and Siege Six are all great examples. New character/gun comes out and it's THE character/gun. All others are almost obsolete outside of niche gameplay. Then eventually they see 90% of the players use the same thing, they have to nerf it. That feels really bad. They're taking power away from you after you've had a taste. GGG does this, but in 3 month intervals so you can adjust. Very rarely do they do mega nerfs during a league and it's usually gamebreaking stuff like ultimate stone farming in Ultimatum league (Empyrian's group got banned for this) and in general do to either Chris's philosophy (he's said it's much easier to give things than take them) or due to their ineptitude style of content release, they do THE OPPOSITE where these sweeping hotfixes and patches come in and the player gets more and more power from when they started. Of course everyone wants it to be perfect from the start and the Lake loot especially was dogshit, but I think everyone would agree you'd want them to make leagues feeling better and better during the league than worse and worse.
TL;DR
-These loot reductions (item squash) were most likely for smart loot implementation later (3.20) that may never happen now thanks to Reddit and Influencers
-PoE is the only game that doesn't introduce OP shit then nerf it during league (Apex, Overwatch, Warzone) but instead gives incremental power buffs DURING league. You can argue stuff gets changed between release and patch notes, but very rarely ever during league launch and some of it is probably just (Hello, Conduit changes!)