You only have had to gone through the implementation challenges personally to know that it’s hard and the costs (to do it by the letter) are high. In fact to do it by the letter you’re going to have to hire a law firm to ensure you’re compliant and they’re going to err on the side of caution and take you down a rabbit hole of implementation changes.

Can you give me a concrete example where the GDPR forces you to do a lot of relatively costly stuff that are not worth doing otherwise?

I did. First hire a lawyer to review your GDPR compliance and recommend changes, and also set up an EU representative who can assume liability.