I have basically the same thoughts as you. The reasons I can think of is:
- Convenience (but SL is pretty convenient)
- Less of a lock-in to one vendor.
- Avoiding filters on sites not allowing aliasing domains (often incorrectly under the label “temporary email addresses”)
I had an issue where one keyboard (worked with another one) worked in bootloader, but not when entering the encryption password after that. I believe I solved that by moving keyboard earlier in the module list in mkinitcpio.conf. Maybe something similar would solve your issue?