I don’t know so much about EGS, but probably some of the following (most of which I don’t use very often, I hope I recall correctly)

• Refunds
• Family sharing of games
• Sharing games for other local users
• Being able to lend games
• Remote Play (with friends)
• Remote Play (stream for a local machine)
• Linux support through proton
• probably more?

What do you mean exactly by organic maps editing tools? I was using organic maps before to add businesses, but now StreetComplete can also do that (and more!). I sometimes use Vespucci because it is very powerful, but it’s a bit of a pain to use.

As a first step, I would recommend checking out osm.org from a computer. Once logged in you can use it as an editor straight from the browser. The embedded documentation really helped me initially.