Sometimes when GOG Galaxy 2.0 starts up, the GalaxyClient Helper Application will constantly have high CPU usage that never goes away. I'll see it last for hours. I tried uninstalling, deleting all GOG folders and reinstalling but it didn't help. Anyone else seeing this or have a work around or fix?

The fact that this post has no response in over half a year is concerning.

What exactly is this helper application doing that demands so many resources?

It's actually the opposite. The Galaxy app is in such a poor shape that if this was a general problem, more people would have seen it...

I'm having the same issue now and your post is the only thing a google search dug up mentioning this. On my main gaming computer with Windows 10 I've not noticed anything, but then again it has a Ryzen R9 5950X.

Now I started using my laptop with fresh install of Win11 and a Ryzen R7 5800H. And immediately after boot I'll notice the fans ramping up, so I check the task manager and notice Galaxy Helper Application is using ~25% of the CPU for minutes at a time, and Galaxy itself using over 1GB RAM. Then it calms down for a bit before it starts up with something at ~25% CPU again. Really annoying!

Did you ever find a solution to this issue?

Did you open a support ticket?
Did you try a clean install?
Do you use third-party store integrations and if so, do you have large collections there?