That doesn't mean you should default to a slower implementation for new code. If you do, you're just creating more low-hanging fruit that nobody will find time to solve.

In most cases you should skip SIMD also for new code. Often a non-SIMD version is required for compatibility, just stick with that.

in many cases often its faster just to switch from debug to release - compilers are good to vectorise many loops. Worth to give it a try before rewriting clean loop/code into SIMD/NEON.