Affinity’s Adobe-rivaling creative suite is now free for six months

Depends on what you want to use it for, but yes it is. Especially since it's way cheaper.

https://www.photopea.com/

For Windows and Mac, yes. V1 was very polished when I used it back in the day, I assume V2 is the same. For Linux, fuck no. They don't care one bit about that OS.