It is a very appealing proposal and that's why I myself have bought games from Steam when I can't find them in GOG. Further, I'm not strict about always downloading GOG offline installers for all my games, even though if I don't I run the risk of losing those games if for example the GOG store closes.
And, as you point out, "so far, so good".
I've just been burned by earlier forms of enshittification and service relationships misportrayed as purchases of forever access.
Also, almost 4 decades of using or in Tech have made me very aware of elements which can affect long term usability of software and hardware.
So nowadays I'll only ever spend money on things which follow that scheme if I'm willing to lose it, even if for now they seem fine, and favour things that I'll have a chance to still make work 10 or 20 years down the line (funilly enough, this week I've been playing Jagged Alliance 2, which is a 26 years old game with gameplay that's still as fun as back then).