My steam account is 18 years old. I can still easily download Braid, a game released in 2009, and I apparently played in 2014, install it on my Steam Deck and be playing it again in ten minutes. Considering it has cloud save support, there is a not small chance that my saves may even be intact.
It's that endurance in the platform that has me coming back. I have faith that Valve as a company is in it for the long haul to act as a game store platform and honor my digital purchases. It's allowed me to put several thousand dollars into them.