Originally Posted by I'm Venom
For use of its most iconic and recognizable character
There's no downside whatsoever for Marvel Studios, for Sony, or for the fans if Spidey exists in the MCU, and vice versa.
The only downside is there's no way in hell you can do this as a one-shot stunt....if the studios try to pull this off even as a 5-second cameo, then fans will be clamoring for more and more and more. Big can of worms there. (Or spiders.)