The fastest USB key are not normal memory sticks but SD cards of a decent class with an USB-C 3.1 adapter
This is the suggestion from Davide Depau, found running several benchmarks with EtchDroid
SD cards are made to put them in cameras and it’s not uncommon to get 300 MB/s write even with a phone.
The slower ones do 100 MB/s on average
Whereas I haven’t found a way to get consistently fast USB sticks. The more expensive ones are generally better but not always. On average, flash drives do not do more than 70 MB/s and after a while they drop even slower when they run out of cache. So do SD cards, but they generally have bigger caches and hardly fill it up with the ISO of arch
Also, in the last 10 years I have noticed (empirically) a substantial improvement in the durability of SD cards. 10 years ago half of even branded SD cards would die on me, now even the ones from the fucking sub-brand on Amazon are OK