How many skills does a game need? PoE, which is apparently the be all end all of amazingness and choice and build diversity, is a game where you use... 1 whole skill, maybe 2 if you're playing one of the few builds that uses 1 skill for single target and 1 for aoe clear. Throw on a movement skill and woo, we have 2 whole skills to use, 1 for travel and 1 for attacking. Then you can maybe throw in a war cry for some builds and have 3.
I do agree that it's most likely 6 because consoles but I also think that is plenty.
The skill tree looked like it wouldn't hurt to have a bit more to it from the little glimpses of it I saw but I also don't think it matters too much because at the end of the day, no matter how big of a tree you make, people will find the best places to put points, post it online, and then that's all anyone will do with their points anyways.
Give one example of an ARPG where this is the case. It's not PoE, D3, D2, Last Epoch, Grim Dawn, I don't think any of the Torchlights but its been a while since I played one so maybe? Or are you just trying to further prove my point that you're another troll in here who doesn't even play the genre but just wants to say the game is going to suck?