I've done assistant stuff here and there over the years at shelters I've worked at. I think if you can find a place that pays decent, it would be more rewarding to work in non-profit than working in a clinic. I was able to do a lot more at shelters than I would in a clinic since everything is OTJ training and they need a lot more done. Some people might think this was unsafe or sketchy... but when vets are telling you to do it and giving you cabinets full of supplies to use...
Thankfully, we didn't do anything that could actually harm an animal, and did get proper training on the job.
I was technically a back up "tech" at the first place I worked, doing all of the veterinary duties on the full time girl's days off. Vaccinating, drawing blood, restraining, prescribing meds for URIs, loose stool, parasites, eye issues, etc.
Another place I did a ton of sub q fluids, diagnosing issues, prescribing meds, microchipping, fecal analysis, and suture removal.
Another place I did vaccinating, skin scrapes, ear swabs, etc.
We basically got crash courses by the vets that came in once a month or so on how to diagnose common issues and what to prescribe for each one. A little informal, but it was interesting for sure.
I work for a non-profit currently, and I would think (maybe I'm wrong?) that the assistants actually working long hours and hard, with the dogs, would make more than the receptionists(me)? If so, they make pretty decent money here working full time for sure, and would fall into your average range.