How accurate are traffic estimates from sites like neilpatel.com

Hey all. Ive been looking at purchasing a site or two on flippa and have been trying to find a site that has an accurate traffic estimate. Ive tried ubersuggest by neilpatel and others and it comes up with estimates like 10 or 100 visits per month when on flippa the site says its getting thousands of hits per month (verified visits on flippa.com). My question is how accurate are these estimates and is there any site you know of that is more accurate?

Why would you mess with any third-party tools? Message the owner, and ask for read-only Google Analytic access.

Not very accurate, at least comparing my own websites' metrics.