If you absolutely don't want to perform any KYC verification, using DEX such as https://bisq.network/ is the only choice.
It's choice that very few would choose due to low trading volume, big limitation for fiat/cryptocurrency pairing and less user friendly.

Otherwise, you should look for other reputable exchange which is less strict than Coinbase such as Binance (usually) or one of your reputable local exchange.


I don't know about freiexchange, but i'm sure many users would choose CoinBase over those exchange when they're dealing with big amount of money.