Right now I would hesitate to buy a used car with 5 years and a 100% of 300 km range but down to 250 km due to battery wear, when I could buy a new car with 500 km range. Owners of first Leafs got hit by already low initial ranges (~120km), so even a 20-30% battery wear have huge impact or car usability. That would change when ranges stops growing (about 700 km, maybe, the same as ICEs?), and used cars have the same range than buying new. 600 km instead of 700 km? Good enough.
Nobody is doing battery swaps yet? That sounds like an obvious thing? Or is the mobile "glued in battery not serviceable component" thinking spread like poison so much that people don't consider it?
If the rest of the car is fine, it should be one visit to a shop to swap out old battery for new (and the shop handling recycling/disposal of the old one), and off you go with car good as new.
I guess the real problem is pricing: right now it is buy used, then swap batteries for 8-10K? No wonder the car deprecates.
I vaguely remember a guy swapping modules of the battery of a Prius at home for peanuts, because the dealership asked 4K for the same service. There are a few places that do a battery refresh for 1 or 2K (eg. texashybridbatteries.com). In the future this might be a good business, today it seems to be a Prius thing... because it was the most successful car a while ago.
Liquid cooled, large EV traction batteries last 250,000 miles. Pre-2023 Prius's are neither, which is why they need replacement.