Naw, they’re tenuously connected aside from some specific moments and characters across the franchise.

Story wise it’s all pulp horror/scifi. If you want to play the highlights, the remakes of part 2 and 4 from the 2010’s are fantastic games and each stand on their own. 7 & 8 are a more modern style and really good straight horror experiences but not necessary to enjoy Requiem. The other entires can be rough as they were created with various elements of game design and language we’ve moved past and improved on since.

Resident Evil Characters wiki page can be a fun read for a little more context but not an absolute need.

Alternately if you want to get caught up without a 100 hour investment in play time, Noah Caldwell-Gervais does great long form essays on video game series’ and his resident evil one will get you up to speed for requiem in significantly less time.

I started playing them on original PlayStation release and have enjoyed them all for different reasons. The story is a hodgepodge of 30 years of writers and artists building a world that is both overly complex and charmingly simple. Each release can be seen as a reflection of the world it was created in and the horror and espionage tropes of the time. At the end of the day though, it is a very silly series that understands the ridiculousness of its characters and world and strikes a great balance between that and being genuinely scary.

Nope, my wife and I watched a stream and I'm only vaguely aware of the plots of the other games. It didn't take away from anything, and my wife clueing me in on the references really didn't add much of value to the experience.