One thing I think doesn't get discussed about Mario enough is actually the role he served (that is, within Nintendo) throughout the early 80s, and a little less toward the end of the decade. A lot of people think of the various appearances of his in retroactively-"canon" games like the Donkey Kong games, Wrecking Crew, and a couple of Game & Watch titles, plus games like Golf, Alleyway and Punch-Out!!, as little more than cameos; but I think it goes a little further than that.
The idea of Mario as an "everyman" has always been popular, but I think that specifically led to him being a really good blank slate of sorts to just... slot into any role you needed. Happen to need someone to referee your boxing match, to pilot your strange Arkanoid-esque spaceship, to light and detonate bombs, to fend off eggplants in a demolition site, or to play golf with? Mario can just be sort of... slotted into those roles.
It's interesting, because I feel like that almost gives him a feeling loosely akin to characters featured in "rubberhose" animation of the 20s up to about the 40s - malleable beyond just a couple of iconic elements, and capable of being changed and altered as needed to slot into different roles. After all, so long as he's got his iconic moustache and hat, it's Mario! And, obviously, Luigi's an easy enough Player 2 to slot in too.
Over time - especially following the success of Super Mario Bros. - it's as though Mario himself was a little more cemented into a specific role, and by the time we get to Super Mario Bros. 3, we're seeing the end of what people think of as "cameos" mostly because Mario and his world really have a quite distinct identity of their own. That being said... it's interesting to look back at a time like this and think about what it might mean for the concept of a "videogame mascot".
Not sure why I felt like sharing this. It just feels like a neat (albeit underdiscussed!) little element of Mario's characterisation from his early years, which... a small part of me thinks could maybe be well-suited with other characters. Like I mentioned, I think Mario's world (and his sheer popularity, at this point) really don't suit him well to the everyman role of a "stock" character in any kind of setting you might need, but it's still a neat part of his history.