See also "pilled."
There's nuance to the etymology of any word of course. In fact I sometimes see the extremely online left try to (ironically?) appropriate "based." But I think in the context we can all figure out which connotation Elon was using.
it's just general internet speak at this point
Lil B
(based ≈ doing your own thing (in a good way)
not swayed by critics)
↙ ↘
Gen Z 4chan
(based ≈ cool) ("based and redpilled"
≈"unswayed by pop rhetoric"
and "sees the world beyond the 'illusion'", resp.)It is also a catchphrase of the extremely online left with exactly the same in-group vs. out-group implication (and, amusingly—because of the different meanings of “liberal” and “lib” favored by the two sides—usually identical meaning with regard to “libs/normies”.)