Anecdote 1: The generic version is way more popular than the non-generic
one in Zig codebase:

     git grep -w alignForward | wc -l
    56
     git grep -w alignForwardGeneric | wc -l
    149

     git grep -w alignBackward | wc -l
    6
     git grep -w alignBackwardGeneric | wc -l
    15

Anecdote 2: In my project (turbonss) that does much arithmetic and
alignment I exclusively use the Generic functions.

Anecdote 3: we used only the Generic versions in the Macho Man's linker
workshop.