Yesterday I bought something on Steam for the first time in many years. (I have a large Steam library, but in recent years I've been getting games from gog and itch instead.)
Since I hadn't bought from Steam in a long time I figured I should read the "Steam Subscriber agreement" that you have to click to accept when you buy something. Let me just say now, the agreement is a very very bad deal for customers.
It goes to great lengths to make it very clear that you don't own anything. You aren't buying anything, you have no essentially rights. You are simply paying for a license subscription to use software with various conditions. Valve is able to end your subscription with no refund if you break the agreement. And the best bit:
Furthermore, Valve may amend this Agreement (including any Subscription Terms or Rules of Use) unilaterally at any time in its sole discretion.
So by using Steam we're putting a lot of trust in Valve; because the 'agreement' basically says they can do whatever they want, any time they want, for any reason they want.
Steam is quite good. I particularly appreciate their Linux support. But they are clearly using their position of dominance to make people agree to unfavourable terms. At the moment, things are fine. But make no mistake - when you use Steam, Valve has all the power. They can screw people over whenever they choose to.
With all that in mind, buying DRM free is better if you want to still have access to the software when a company decides to change direction for whatever reason.