I think Mario, Sonic, and most of the scrolling games are available for all platforms. You can pretty much find them online easily. And there seems to be many editions over the years. So you may have to choose what to play there.
Yes nintendo has protected their baby for many years. It would take so much money for microsoft or sony to buy that from nintendo. It's kind of like pokemon. It will always be a Nintendo type thing. Fortunately the Nintendo Switch has all these games on it or the Nintendo 3ds. Whether you prefer handheld or an actual console like the Switch. But yeah it wouldn't happen in our lifetime at least I imagine
I mostly played through the console on other platforms. So yeah that maybe my experience. I have also seen mario got jailbreaked on other chinese consoles which are sold cheap. Usually in asia, many such cheap consoles have sonic and mario in them. And they have like data card which has same mario games with difficulty of higher levels but same game.
I want to say it's one to one, but in all honesty I'm a bit fuzzy there. I can recommend JoyFreak's sister site AdminIntel - Admin & Webmaster Resource where there are lots for people of varying degrees of expertise with development, you likely can get a far more precise answer there!