The problem with your logic is you're listing movies from 10-15 years ago as proof that Spider-Man is fine without Marvel's involvement.
"ASM" 1&2 did not perform how Sony wanted. Which is what led to Marvel's involvement in the first place. Again....Aunt May movie.
So the last movie prior to "Venom", that Sony was happy with, without Marvel....was "Spider-Man 3"....which came out 12 years ago.
All this, coupled with the fact that Sony's movie division has been on the brink of collapse for a decade, if not longer....yeah. I don't see how anyone in their right minds can think this is good for Spider-Man.
Fred.