microSD cards don't really cut it for a general-purpose desktop in terms of lifespan and reliability and SSD over USB is an awkward workaround at best. Hopefully the RPi 5 will have NVMe or a SATA port at least.
Every Pi SD card has ended in irreparable disk corruption. The SD hardware’s wear-leveling and delayed allocation is fundamentally incompatible with any device without a battery, especially with frequent writes.
The “official” solution for the Pi is to use read-only SD cards with overlayfs. That’s not the default and it’s not how entry-level users will use this.
Also, don't under estimate the performance of future SD cards.
v0, get it shipped
v1, improve
https://carcamcentral.com/guide/recommended-microsd-cards-fo...
I know there are other power down issues with SD cards and corruption well. I think in a class setting I would have important files replicated to an NFS server, with at least hourly snapshots.