When I start Steam on Linux (specifically Pop!_OS (Ubuntu-based)) it takes a good long few seconds to open, and there is no loading indicator of any kind. When Steam needs to update it is even worse, it just took probably close to 30 seconds to show any activity whatsoever and then finally it somehow indicated that is was doing an update. Brand new PC, has done this since I installed Steam. I kind of got used to the delay but I thought it was broken today and was never going to start, but it was just an update.