Regarding the two Russian A50 shot down during the Ukraine war, but it would also apply to US style AWACS.
Beside the price-tag of the plane itself, I would expect that the crews operating the radar are also highly trained, and that if it may be even harder to train a crew than to build a new plane.
I know, that something as simple as pulling the big-red handle on your paraglider harness is pretty hard when you’re in a severe flight incident dealing with G forces and the ground moving full speed toward you, and I imagine it’ll be even harder on a large plane, where you need to access a escape hatch, most likely in a burning and depressurized cabin while having no idea where is up/down due to the G-force and the rotation. However, when flying a plane which like a high value target for the opposing army it would at least feel more comfortable to know that you have a low but non zero chance to escape if you’re shot down.
I can’t speak to a Russian plane but I can speak to it from the US side. Wearing a parachute and survival gear makes it nearly impossible to do your job, you can barely walk around in it. Also If training Russians is anything like the US aircrew’s training, you really only practice using the gear on the ground and once every couple years. Going into a combat zone you don’t expect to have to use it and it’s essentially just sitting there in a closet. And not only do you have to have the presence of mind to put it on, but you have to strap on your crew mates gear as well. Then find the usable door. Then jump out of a plane which you’ve certainly never done before. Unless you’re in a slow controlled descent it’s basically impossible to do