I did say that LET is a legacy command leftover from the "original" version of BASIC.by Solitaire (Login Solitaire1)
Nothing is older that the "original."
GWBASIC was NOT the original, but an offshoot. LET was was required by APPLESOFT BASIC. I know Commodore BASIC didn't need it. I mentioned GWBASIC because it came just before QuickBASIC. It was the same as BASICA, a proprietary version used by genuine IBM computers. BASICA would not run on clone computers because of a slight hardware difference, copyrighted by IBM. The A after BASIC in BASICA stood for "Advanced." GWBASIC was identical except it would run on all compatible computers, not just on IBM.
By the way, I still have a copy of GWBASIC on my computer and I just ran it to make sure that LET was not required.