The big deal when I was in school was the EcoR1 mutant. It was E. coli with the restriction and modification enzymes removed. That left the organism defenseless against insertion of foreign DNA. You could insert a sequence for something useful like human insulin and get the organism to replicate massive amounts of the protein.
Converting this knowledge into useful gene therapy would be awesome, but the barriers seem huge.
I wouldn’t envy being most kids today, except for being kids talented in the sciences.