That’s the beauty of Tailscale, you don’t have to trust them, because they don’t MITM your data, unlike with Cloudflare. I’m sure the employees of Cloudflare are nice, but so are the employees of any company, good or bad. It’s not that Cloudflare is necessarily bad, but you’re putting them in a position of trust over the content of your data you send through them, as opposed to trusting no one.
I’m sure most of the people who work for Google are very nice people, but people still switch to self hosting for the privacy and control over their own data, and the same goes for Cloudflare.