Mgtow was not met with indifference. They've been consistently criticized since the movement first started, and they quickly evolved into a cabal of Nazi-adjacent freaks. Fuck those guys.
There may be some good that could come from a men's movement for self actualization and improvement, but mgtow sure as shit wasn't that
By percentage, but the total birthrate would (continue to) go down.
And now Trump's gonna make it harder to immigrate, so the population may actually start nosediving.