It's because they're a privately owned company.

The pressure for enshitification mostly comes from shareholders. Without them, the company can actually think about their long term future and decide exactly when and when not to increase profit.

I tend to avoid proprietary things whenever possible these days, but I found most things by small, privately owned companies are pretty good towards their users.

Well they did try to sell paid mods and push pay-to-play in the steam marketplace with Artifact, but luckily they ran it back. Steam is super good now but don't get too comfortable.