Hi,
I think Skyline would benefit to have a Steam version.
Despite Steam or country taxes, Steam has a huge benefit for 3D engines of exposure, the number of Steam buyers revenue will quickly overcome the revenue on Skyline site with very low exposure, this is a good point to consider.
Other software like Substance Designer has their own site, but they also wanted more exposure to indie and users that doesn't work in game industry, so they also sell on Steam, and despite taxes, it's another big source of revenues for them.
There is many ways to distribute Skyline on Steam, it could be a limited or starter version ( like no multiplayer , no visual scripting , or no customizable splash screen ) , so most hobbyst and amateurs could use it while more experimented users would buy a more complete version on Skyline site.
Skyline is not ready for prime time (bugs, export, fbx, essential features missing), but it could be ready this year, so Steam is something to consider otherwise it will stay as a niche and not known from indies and others hobbysts.