It is a known issue, it balloons based on friends lists, game catalogue size, animated animations, notification settings, blah blah blah. It’s been an issue since Valve launched the updated interface back in 2018, the added features they crammed in created a number of memory leaks. The more features you use or leave on the worse it gets.
But like many memory issues it’s not a precise thing, lots of factors at play there.
Windows doesn’t get hit as hard as Linux does because Microsoft has spent decades cleaning up after poorly coded software so the Windows Garbage collection process is pretty good. That’s also why if you watch the webhelper processes in windows they come and go. As they leak memory garbage collection cleans up after them they crash one of the processes and another pops up to take its place.