Well, perhaps then schools need to be fixed? Memorization is a skill like anything else, and it can be trained via a variety of ways (memory palaces, mnemonics, writing stuff down by hand).
If a student can't remember ~20 non-trivial entries in the multiplication table, then they likely will struggle with anything else non-trivial.
> There's some value in finding an approach that works for everyone as an educator instead of one that works for Most if you can do that, I think.
Also known as "dumbing down the education".
There are trade-offs everywhere. The lattice method simplifies bookkeeping on paper, but try to visualize it for mental math and you'll likely fail. While the classic textbook algorithm is fairly easy to do.
So the lattice method is optimized for a use-case that never really matters in practice: being able to multiply numbers on a piece of paper, while not having access to a calculator. While it's pessimized for a use-case that actually matters once in a while: pure mental math.