Yep, for steamdeck your options are to install windows or to stream. Greenlight is a good linux application that handles the streaming better than the website imo. It can also do remote play if you have an Xbox, which generally has much lower input latency.
Most of what I have seen on the meme communities I follow have been par-and-course with what I expected to see on internet. Although I agree that it is morally wrong to joke with malintent when someone passes, I think humor is a normal response to tragedy. As long as the memes aren’t egregious about it, then they still get a chuckle out of me and help me feel better about the situation.