This just happened to a neighbors minivan. Rear ended on one side but didn't look all that bad. Slight wave in one quarter panel. tailgate panel, one light, and the plastic rear bumper tore up. Insurance company told them parts are hard to locate right now and body shops are too backed up to get it repaired in a timely fashion so they totaled it due to circumstances they can't control. The thing still ran and drove just fine so I don't know why the insurance company would not let them wait until it could be fixed later? They ended up getting a check for it and a tow truck came by and grabbed it.

Today with used vehicle prices so overvalued I would be wary of being able to buy another comparable vehicle for whatever money they give you. I suspect your going to get the short end of the stick and have to spend more of your own money to get yourself back into a comparable vehicle.