Well no, I don't think porn "decided" that. Beta was better quality, but more expensive and not "better" enough to warrant it for most home consumers. Sony also marketed it poorly, and capped beta tapes at 1hr.

Sure the porn industry sold home tapes, but they didn't sell them on VHS because "you'll use a VCR and like it by god," they sold them on VHS because most home video consumers had VCRs due to them being cheaper than beta machines/tapes. Easier to sell them a VHS tape for their VCR than to convince them they should have bought the beta machine.

CDs won over cassettes and carts because they are better, they sound better than tapes and (at the time it was believed) they last forever, and they could fit more on them than contemporary carts. They physically take up less space than the (video) cassettes too, which mattered in the days of shelving (instead of HDDs). It wasn't just because nintendo said "nah fam we like carts" and sony said "we like the shiny bagel," the consumer also liked the shiny bagel.

Now people have stopped buying disks and soon disks will stop being sold in favor of download/streaming only, this isn't because some shadowy they've "decided," it's because the people have decided not to pick up physical copies of disks anymore.