Fortran and Cobol used to be "FORTRAN" and "COBOL", too, but once systems with support for upper- and lowercase-letters became widespread, they went mixed-case.
I recall there was some debate if the name BASIC had been intended as an acronym initially, but in time, evidence (AFAIR, anyway) tended to support the claim is was an acronym from the very beginning. (-:
https://www.dartmouth.edu/basicfifty/basic.html
True BASIC, a company that Kemeny and Kurtz founded in 1983, is all upper case too.
Love it or hate it, BASIC has left a footprint in the IT world that few languages could match.
COBOL is still “COBOL” (at least per the IBM page on the language and the ISO/IEC 1989:2014 standard for the language.