No. The industry is currently facing a quality crisis BECAUSE of playstation and, to a lesser extent, xbox. without it, we would probably be getting much more games like the ones from the 90's and before.
"Without Sony and MS, the industry would be much weaker with just Nintendo and Sega, a 3rd console manufacturer could enter but I doubt they'd be as serious as Sony and MS. I can imagine a few companies trying like NEC etc"
Why would it be weaker? two is only behind a single company as the best number.
"So my conclusion is, without Sony targeting the young adults and +30 age groups"
This myth should be forgotten. video games didn't change with playstation. we got the same games as before + the ones made possible with polygons. Sony didn't target adults, they simply liked the games, games that would be on other consoles if playstation wasn't a thing.
