Most folks that I know around here won't call one unless they're horse people. The large animal vets we used to have close by all retired or quit. The ones further away always have a waiting list a week or so long and if it's an emergency, it'd likely cost you as much or more than the cow or calf is worth to have them out. Lots of older farmers I know got a bad taste in their mouth from historically calling a vet out and paying them just to have them tell them the cow or calf was gonna die anyway and there wasn't much that could be done.
With the plethora of accurate information available online and medical tools and supplies at reasonable prices, if you can get your hands on the medicine from the vet then short of invasive surgery just about anything that needs done can be done by the owner if they've got the time and the confidence. Granted, I don't AI, preg check, palpate, etc. and it might be different if I did.
Honestly at my place, they either make it or they don't. We'll worm and doctor up normal ailments, pull calves, try to fix a prolapse, pinkeye, etc. but the animal still has to make it through and live. If they don't it's just the way she goes sometimes.