TLDR: The gameplay is fun but many things around it, make it hard to really recommend this game

I really wish i could like this game more. Theres so much to be loved here. And thats certainly visible since destiny has many players. Many people like this game. Heck i played Destiny 1 really heavily myself. Every DLC and raid and everything. And yeah it was great. You can have great moments playing this game, theres no denying that. And that goes for Destiny 2 as well. Yet i dont think the game itself is overall good. There are certain design decisions that are horrible. But for many people its just worth to stick with Destiny cause the gameplay is just that good. Still i wanna present a few of those bad design decisions.

monetization
The free to play part of this game is more of a trial of lower level content. Its probably a pretty good strategy since you will experience the gameplay (which is very good) and will be hooked in. But to "properly" play the game and get the most out of it, you will need to buy the season pass and whatever DLC comes around. Otherwise the game can feel a bit starved for content or you feel excluded since everyone is doing the new activities and getting new loot, but you cant participate. Id estimate the cost at 100+ bucks a year, depending on how many/big DLCs get released. And yeah honestly that sounds fine so far. If that was all i wouldnt even consider it a problem, since the quality of content usually is very good. But there are more micro transaction for armor transmog or skins. Yes those can be bought sometimes for free currency but its still very limited.

removing of content
Removing content (that was paid for in some cases) just doesnt sit right with me. The technical reasons stated by Bungie make sense, yet they are not the problem of the player. Bungie digged its own grave there and the game doesnt feel ever expanding as many other games. Its more of a constant change, which some people may like, but personally i dont like it at all.

badly designed time filler grind
Yes Destiny is a looter shooter and grind is normal. But the way this is implemented is just baffling to me. The light leven grind every time its increased is just uneeded. It locks players from the actual great content of this game like raids. It just serves to prolong playtime. Restricting activities where you can get gear that increases your level makes it just worse. I understand pushing new content, but id play that content anyway because its fun, not because the game forces me basically into it.
Another problem are challenges/bounties that require "kill x enemies in stikes" or something along those lines. Since Destiny does not have any real way of playing a strike solo. Therefore it either becomes a competition of who can kill all the enemies first or since others might only need strikes finished, one person rushes to the end and the other two fight for kills. Forcing people into that is so backwards in my opinion.