It's not that SD cards don't have advantages, it's that they also have noted disadvantages in terms of speed and reliability, particularly when you factor in that people don't always buy the high end models.

In a time when computer programs habitually assume fast storage, running your operating system and primary runtime on a microSD card is weird. Even "fast" microSD storage usually isn't unless you buy cards that cost as much as the SBC in the first place. If you want some perf in the SD form factor you go to the full-size card--that's one reason cameras still use them--but even there you encounter pretty hard limits, which is why higher-end cameras have also gone to SSD-over-USB-C and CFExpress Type B.

eMMC does not have to be soldered-on, either; the Orange Pi 5+ has a swappable eMMC module.

This is the pi5, not the pi1. Technology marches on. Maybe the SD made sense in 2012, but that doesn't mean it still makes sense in 2023.