the author of the site makes no secret that the website is vibecoded. You're unfairly extrapolating that the product itself is vibe-coded (hard to do unless he is a time-traveller). And you're missing the point of the unique advantages that L offers wrt computation on compressed data.
that is fast! Are you going to do the STAC-M3 benchmarks? Kx use them as evidence that they are the fastest, which is a fair claim as nobody else participates in that particular test :-)
q is the programming language underpinning kdb+ by Kx Systems - often claimed (by Kx) to be "the fastest database in the world". Possibly also the most expensive?
L is an independent implementation of a q interpreter. To those who reluctantly commercially license kdb+ - this will be a welcome alternative.