I tried actually looking for anyone who actually did experiments to confirm whether or not software is getting slower and... uh... I can't really find anyone who has done such an experiment. Possibly, this is just the shittification of search, but everything that turns up is essentially just a link to a thought piece on the bloat of software, which almost invariably degenerates into shitting on Electron.

On anecdotal evidence, one thing I recall from the late 90's/early 00's era of computing is the sheer prevalence of splash screens. If you wanted to open an application up, the first thing it displayed was a splash screen, with a progress bar that would animate to show you that it was doing something. And these splash screens have become far less prevalent in modern software, which at least anecdotally throws some doubt on Wirth's Law.