Why buy? If you do some research and have a bit of knowledge - you'll save an awful lot of money. The average monthly car finance payment today is around £400-£450, that's approx £50,000 over a decade. If you buy the right used car and keep it for a decade, you'll save an insane amount of money. Just imagine you haven't got those car payments and are putting the equivalent money into an index fund that accumulates over 10-20-30 years. You're potentially talking about a very nice house, cottage, villa abroad, etc.
It's the whole mentality that's wrong. People go to work (often miserable) and sign up to liabilities that are in line with their salary. People get their wages and feel like they have to sign up to these liabilities to compensate for going to work. A subscription service and locking you in is what any corporation wants their customers on. Hence why motor dealerships don't like people buying cars, they want vehicles going on PCP, HP or leasehold contracts.
With regards to used EV sales increasing, they had to as people haven't been buying them. This means the price drops and sales increase. But crucially the sale of new EVs are in decline - this means the used market will suffer long term. One is connected to the other. Obviously it will be interesting to see where prices go with new EVs, can the manufacturers make the business model work? We've already seen Apple get out of the game plus several other companies going bankrupt.