Graphics thing is straight inaccurate, and gameplay was changed noticibly… Although the latter point is a negative. Ability cooldowns being excessively long being the most common gripe I see.
Main issue Destiny 2 has is lack of endgame content. Most activities don’t have levels of difficulty or payoff that make them worth it. Especially at higher levels.
Mechanically a lot of players complain about how Destiny 1 at the end of its lifespan had better features and gameplay as a whole. If anything “Destiny 1.5” was what Destiny 1 was during Age of Triumph. And according to the community as a whole it would seem that was a good game.