A lot depends on whether the speed of the microSD card will improve or not. If it stays at around 10 MB/s, then it is going to be painfully slow. I don’t want to take photos/video at that speed, so I are going to use the eMMC storage, and that is going to fill up rapidly. When I work with large documents in LibreOffice on my Raspberry Pi 4B and a microSD card, I basically have to stop working for 20 seconds every 5 minutes when it autosaves. The wait time is going to be even longer with the Librem 5 due to its slower microSD, so I doubt that I will use the Librem 5 as a desktop PC.