That’s what I thought, and Revolut with lots of cash on it worked in Germany, Switzerland and Spain for me so far. They just locked up some amount and it was all fine. But then I was in the US for a business trip, and none of the car rental services would accept it. I checked all 6 companies at the airport and they all immediately said “no loaner cards”. I had like 4k on it and told them exactly that, but they said it’s against their policy.
Same for me. The funny thing is when they don’t know Revolut and just try it, it works like a regular credit card. When I go on holiday my balance at Revolut than is higher than my credit line anyway, so it shouldn’t matter.
Take a look at 2em.ch. This is a platform for renting vehicles from private individuals, and is generally much cheaper than rental car companies. 2em provides insurance, etc. so for you as a renter it is just like renting from an agency. I rent out my car on this platform, and have not had any issues so far.