Not that I'm necessarily disagreeing, but simde has made life a lot easier here. If you want to write SIMD stuff and don't want to use a higher-level library or depend on the compiler to optimize the code down to SIMD (both of which honestly seem like pretty good options these days), simde is worth taking a look at. You write code that looks like native code, but it'll translate it to the other archs for you. Well, "other archs" just means partially-supported NEON here, but I'd still consider that quite a win.
No relation with the project, just a user.
I don't know what a good way to compare these might be, other than perhaps activity/contributor count.
[1] https://github.com/simd-everywhere/simde
[2] https://github.com/ermig1979/Simd
[3] https://github.com/google/highway