Librarian trading 1.20.30 changes

Would be nice to, instead of having an specific type of villager to have some enchantments, have all villagers having enchantments as just choosing the base enchantment (like first trading is looting I) and then at max lvl of the villager u have a chance of getting either that enchantment at max lvl or one rare enchanted book, same or kinda proportional value. Lets say i want mending, this would obviously be a better chance to get it since u only can get it at max lvl of villager, then either u can get (choosing fortune I at base lvl) fortune III or an enchanted book of a similar value lets say unbreaking III.

I do argue about the fact that the transporting villagers from biome to the place u want its too difficult, i dont say its not broken the usual trading mechanic but it just need to be adjusted, make it not the first chance to get it maybe the second or the max, but make it so u dont waste lots of time and materials just to get something u didnt want.