> For example, it wouldn't surprise me if, the next time Marvel decides to make a new adaptation of Spider-Man, the spider will have been treated with mRNA instead of radiation (the original story) or gene therapy ('90s cartoon, '00s movies, maybe others).

mRNA vaccine tech being discussed here is not gene therapy. It cannot (appreciably) alter host DNA the way radiation or gene therapy can. It simply causes the host cells to manufacture desired proteins for a limited amount of time.