I don't think any technical-oriented people in this thread would agree that they have "little incentive" to allow Google Search personalization. When I turn off Google Search personalization, I get inferior search results that are less likely to be what I was searching for.
If you don't want your results personalized, there is an option in the search results to turn personalization off.
The problem I have with this law is that Google will need to default to non-personalized results and then prompt users if they want personalization. Google probably doesn't want to increase UI friction, so they will most likely just disable personalization and not prompt to enable. This will result in less-engaged users and inferior search results for the average EU citizen.