Im using P3Dv4 and still have no problem with it. All addons still support the platform. I will think of moving into MSFS but maybe in the next 2 years when most of the addons move there.
it really depends on your graphics card, if your graphics card's got enough vram, say 6gb is a good amount, then definitely go for v5 my p3dv5 constanly crashed due to lack of vram when i was still using the good old 970, then upgraded to 3080, butter smooth!! ;)