> but my point is regardless to compare a language like English that has a grammaticalized future tense via auxiliary verb to languages that don't grammaticalize future tense.

These humongous walls of text sound rather like "and therefore I choose to define what English does as 'grammaticalize' and what Japanese does as 'not grammaticalize'".

> I find the "Mysterious Japanese mind" trope orientalist and stupid.

Then maybe have another think about why you're coming off as if that's exactly what you're doing.