Because they are one of the few mega companies that hasn’t shrinkflated, enshittified, or otherwise crumbled the quality of their offering. Haven’t sold out the privacy of their customer base to advertising companies, and are generally good to deal with for customers and developers.

It’s not a secret formula that no other company can learn from. It’s as simple as not being dicks IMO.

For some reason, most companies seem to grow too a certain threshold at which they sell their souls to profit and will self destruct to get more of it. Steam thankfully isn’t one of them…… yet.