Something I see people say a lot is that the guns are boring. We definitely have a reduced perk pool and no more random rolls, but to me this is a relief. I didn't hate random rolls, but playing in Destiny 2's sandbox, I enjoy shooting more than in Destiny 1. I've tried way more guns, I've kept more guns than in Destiny 1 as well. D1 had an issue where Bungie developed a set of all-star guns and realized they made their best-in-class guns for their entire Year 1 (Fatebringer is a great example of this). So when they had to dial it back in order to make room for more guns to enter the sandbox, it was already ruined. "Bungie took away my Fatebringer! Bring back Year 1 guns!". I think we all have read atleast three posts a day saying this for since The Dark Below launch! For me it's super aggravating because I WANT new guns in the sandbox, and I really don't mind having gun power turned down but gun uniqueness turned up. That's what I feel is in play now. It's definitely happening in the Exotic weapon department, which is why we hear the criticism that Exotics are weak. Each one feels unique though, either they feel like the ultimate version of an archetype (MIDA Multi-Tool being the ultimate Lightweight scout model, encouraging that playstyle) or an entirely new style of play (Coldheart and Fighting Lion). This is different than D1, but I don't see it as bad.
Could it be better, should it be better? Yes, and that's what updates and DLC are for. It's not a terrible thing to have new and old guns introduced in free updates, and it could be that push to log back in after a break. Instead of logging in after a break thinking "Oh, I have to finish getting my raid gear" or "I never got an Imago Loop, I should grind for it", you can have thoughts like "Oh, it's Faction Rally this week, I gotta get the new FWC gun." or "Iron Banner is up this week, I should finish my set". Then a couple weeks later you have new content to actually dive into in the form of DLC. From what I've seen, the idea of new rewards has kept some above average to casual people checking in on the game, because as players we can all get burnt out on the grind. You'll see the same consistent people grinding on Destiny all the time, but you see everyone on your friends list online when new content drops, just to check it out.
A final point that I'd like to bring up on the comparison to Destiny 1 and 2 is that I feel that Bungie chose to build a better foundation in Destiny 2 than just continuing to build on the creaky foundation that is Destiny 1. The world in Destiny 2 is way more vast, there are way more interesting battles that can happen in the sandbox. There is a real campaign to get you into the game, and Adventures that can lead you deeper into that.
The systems in place for giving Rewards are consistent and can be improved on. The shooting itself is some of the best in the industry. Most importantly, there is actually stuff on the way and we know about it, and there is precedent for free updates. So things can actually get better instead of having to wait an entire year for a "Taken King" style expansion (and a $40 price tag). There are more possibilities for improvement, which is why critical feedback is super important.