Yeah, I intentionally left out BECMI as I never played it as it was starting to bloat like 1e. B/X is far simpler.
I'll say it again, 5e is a lot like B/X, but with modern mechanical techniques. I didn't say 5e was more complex, just 1e,2e,3e. Then 4e tried to simplify and messed it up. 5e got...