EGS has yet to reach the feaure parity of Steam from 15 years ago.

The Epic Game Store is just kind of mid. The app feels spammy, the game selection is less, and it doesn't really offer anything over the existing options beyond the monthly free game gimmick. If they want customers to head there it needs to be better, not just good enough.

Who knows? Presumably because Steam hasn't done anything to drive them off, they've generally been satisfied with the service, and the titles they want are available. At least that would be my guess based on my personal experience but I assume Valve has a much better grasp of their audience than I do.