I don't mind impossible things happenening in a "grounded" setting. They already implied the world took place on Earth from the positions of P13 at Tokyo, the Japanese town, and the sweeping shot of Earth from space, they implied the Adults gave up society for immortality, and that they retreated into plantations because of Klaxosaurs. There really wasn't anything 19 did that was relevant, outside of Werner and Klaxohime.
His pursuits of an evolved humanity? Droppled plot point because muh Apus.
His immoral cloning? Doesn't really matter.
His "wife"? Basically useless, just a Gendo parallel to show him going off the deep end.
They also took until an episode later to show that FranXX were build from Klaxosaur bodies, even though it was obvious in 19.
19 also feels totally incongruous with VIRM even though it shows that the 3 founders were non-human, it just feels too serious and "conspiracy" like Evangelion, rather than some crazy alien society like TTGL.
19 and 20 are just so contradictory, that you basically can't pick both of them and have a congruent story, either go with something grounded and have humans give up their fertility and society for immortality and were immoral adults fucking up earth for the new generations, or skip 20 and have an evil society manipulating Earth's leaders, and actually give screen time and reason for it, rather than a generic purposeless hivemind.