And why would you buy bitcoin on eBay? There are specialized platforms where you can do this. Such as centralized cryptoexchangers, like Binance. Not the best option, but definitely better than eBay. 
The solution to the issue of purchasing bitcoin using Bisq or BestChange is, of course, much better in view of the absence of KYC (in some cases).
Back when I was first involved in cryptocurrencies, it was supposedly a way to purchase crypto, mostly Bitcoin or Litecoin, with PayPal. As another poster already mentioned, eBay banned the sale of virtual currencies, in 2021. It was actually quite common loophole to acquire crypto, while KYC was far more lenient those days, I'm talking about somewhere between 2014 and 2016. I remember because I had my parents PayPal and it was the only way I could find to buy, even though I never proceeded. The solution to the issue of purchasing bitcoin using Bisq or BestChange is, of course, much better in view of the absence of KYC (in some cases).