I’m not a film historian so I can’t really give you a rundown on the how and why actors get paid the way they do now and how shitty it was for so long before. I can give you the shity answer of its art, it’s speculative and the studios will make money off their work for decades once filming ends. AND, unionize.
The tech industry is a cesspit of exploitation and it’s not gonna get better unless y’all unionize and fight for it. I can’t fathom how residuals would work in the tech industry outside of those adjacent to the arts for things like CGI and stuff.