It been downhill since they went Electron, I don’t remember the old app taking more than 3 to 4 seconds. Since the Electron client loading times have been unpredictable sometimes 5-10 seconds and sometimes to around 30 seconds even though no updates available.

Edit: CEF

GIMP is as robust as Photoshop, although from scratch or transition may be harder to use? paint net is a middle ground.