It definitely feels way different compared to the previous generation of groups, I think after the globalization and success of Kpop (mainly thanks to BTS) companies see the potential to have "the next big thing", and they try to debut people as young as 13 just so they can appeal and relate to the majority of Kpop Stans which are teens/young adults.
Also the choreography of 4th gen groups seem more complex than 3rd gen, mainly ggs tho.