We have Radon here. When we were buying our house, they didn't have a mitigation system installed. Test came back 17! Seller paid for the mitigation system to be installed.
Below 4 is the recommendation. No one, with any experience will blink with a .8. No one that lives in an area with radon and experience will blink at a system being installed. They will be happy there is one. As mentioned, radon mitigation is just a fact of life in certain areas.
But, with a mitigation system you have to get it checked periodically, as the fans do wear out and need to be replaced. The company we used for the mitigation system, had a 10 yr warranty if we checked every 2 years. It can start to creep up. Ours, about year 6, did start creeping, and this last time we had to replace the fan, because it went above 4.