Destiny 2 is playable, but it's more demanding than Overwatch and Rainbow Six, so you'll probably have to use low/medium settings or lower the resolution to get 50-60fps. If that's okay, then the Rx 550 is a good choice.
The AMD GPU recommended for min. reqs was a Radeon HD 7850 2GB. If the RX 550 2GB is on par with it then it's no problem.
There's no need to compare GPUs. I looked up people playing Destiny 2 on an Rx 550 and saw that low/medium at 1080p makes it run at 50+fps. That's not necessarily a problem, but it is for some people, especially since future games like Destiny 3 will run even worse.
Its okay man. I posted on r/buildapc and they helped me out. Thanks for the help though.