From Valve .
"
We’re always working to improve Steam for both
players and developers.
Visibility on Steam is driven
by fans and the games they
buy and play.
Our goal with Steam is to
match games with the
players who will love them.
All kinds of games can find an audience, and success, on Steam.
There’s room for
everyone. ""
I can't say for certain about Nintendo (but I shouldn't be surprised if it was, but I'm having doubts about it being true seeing just how insanely bare bones the eShop has been since 2017, I don't think it ever got any major updates or anything)
But for Sony and MS sadly they are the opposite of this.
"
We don’t sell
advertising
or placement
We don’t think Steam
should be pay to win.
Not selling ads levels the playing field and makes
recommendations better for players.
You don't need to work with an editor to get featured.
You don’t need a secret handshake or know the right person on
the inside.
Most visibility on Steam
happens automatically. "
And it's because of these features that
"
We’re surprised all the time by the
games that blow up."
All of this is from some slides that Valve made about store visibility for devs.
A lot of that I would say is what leads to Valve not having to spend nearly as much as the other 3 when it comes to marketing cost (the number of ads I've seen for Nintendo are something else.
Seeing how little interaction Steams X page gets, along with their YouTube channel, it makes sense as to what they do so much to invest on improving the store experience. It's why 20 years later they are leagues ahead of the other guys.
eShop is bearbones, MS sells screen realastate to any one willing to pay (MS please stop showing fortnite in the sponsored section of the Xbox homepage. As for Sony they heavily curate stuff (which is both good and bad), hey want to check out what PS5 games Yoko Taro recommends? Here you guy, also check out what games the PS staff recommends. You want stuff more personalized for you? Good luck with that. At least they have a nice little end of year personalized summary for you.