I wrote my first MIXAL compiler while I was in High School in 1973.

Writing a BASIC interpreter is only a little bit harder.

http://cini.classiccmp.org/pdf/DrDobbs/DrDobbs-1976-05-v1n5.pdf (PDF)

Version 3 in 8080/Z80 assembler is here at github. Select RAW to download the code.
https://github.com/pvmm/tinybasic/blob/main/tinybasic.asm (web page)

There are a couple of BASICs available for iphone and ipad.
Only one seemed decent on mac (or Linux, I am sure) gambas.

Reason? For anyone who ever learned BASIC, it makes a great programmable calculator (check the floating point and decimal arithmetic support!) rather than learning another programmable calculator language, of which there are several.

For anything fancy use PocketCAS, or some other CAS, like Maxima, or for matrix calcs, Octave (clone of Matlab)
https://www.ubuntupit.com/best-computer-algebra-systems-for-linux/

i saw recently a basic called basic for iphone . figure one is enough. thanks for the historical info.

less and less memory. The less memory needed, the more widely used, back when memory was a precious commodity.

apparently some languages are better for certain purposes. My Son The Astronomer is writing a program in a language that I can't recall, but it's not one of the ones we'd all at least know the name of, but one that is apparently very good for astronomy.