I don't know if it's that, especially now that AI and other technologies are about to make it much easier to do more with less people. It's going to be a shitshow when AI starts replacing jobs en masse, and denying abortions and contraception is only going to make it worse.
The main reason, and probably the reason why the rank-and-file middle and lower class conservatives are going along with this, is because they think we need to outbreed the scary brown people. Yep, it's the Great Replacement Theory, and this is what the lawful evil conservatives are doing about it instead of shooting at minorities in stores and houses of worship. They just can't stand the idea of us being replaced by Muslims, or replaced by Mexicans, or any other non-white and/or non-Christian minority you can think of.