I'm like @SWAINEY84 and I've been playing since the D1 beta as well.
Honestly, the biggest reason I stopped playing was the lazy copy/paste development issues, as well as the season model. I HATE it. H-A-T-E IT! Remember dropping a bright engram every time you hit another level at max? What was wrong with that if the reward was cosmetic? Ever since they implemented the season model, it's been monetized more and more each season. I'm just done with it all, especially with the aforementioned copy/paste design. The balls to call old weapons, armor, and areas, "new" is just absurd and disrespectful. The last season was honestly the tipping point for me. It's gonna take a lot to get me back into it.
Also, Why should I have to wait a week to play a story mission? The biggest thing is, If I went back and replayed D1 from start to finish, I could replay the entire story from start to finish. You can't do that now with D2. I get the size of the game hurt performance, but that's what sequels are for.
I feel like the shit started with beyond light should have been the start of Destiny 3. The foundation is there already. Improve on it.
Thankfully, the biggest saving grace in all of this is I've had the chance to play some really good, and not so good, games as of late that I probably wouldn't have had the chance to thanks to D2 addiction.