hmm maybe it's faster reading than writing on it?All I know is, I went from a cheap-ass 128GB Samsung EVO class 10, to a 128GB Sandisk Extreme A2, and the speed difference is night and day. I can put games on the card at 78-ish MB/s, instead of 20-ish MB/s. Homebrew and games load up quicker too.
"Well, here the Switch isn't quite so future-proof. The console only supports UHS-1 cards, which have a maximum possible speed of 104MB/s, compared to the 312MB/s speed limit of the more modern UHS-2 standard." So here we got it. If you want speed, go for speed.