Look man I get that you’re not very tech literate and as a hobbyist that’s perfectly ok but just because you don’t know much about technology doesn’t mean the technology doesn’t make sense. You wanted to know what’s different and I told you, you wanted to know how and I told you. If you still don’t understand something then you need to articulate that and ask an actual question. It took me years to earn a degree in network engineering I can’t just distill all of that knowledge into a single comment for you to cover every possible dependent piece of knowledge that you’re lacking because all you can communicate is “I don’t get it”. You have to be specific on what it is specifically that you’re not getting.
I will indulge you again here under what might be a false assumption that you genuinely want to know the answer.
Cloudflare MITMs your traffic because that’s how it was designed. Your traffic is encrypted to their servers, de encrypted, then reencrypted between Cloudflare and your server. They can see and modify any data you send through them. All your passwords, tokens, and personal information are readable by Cloudflare. Therefore there’s an incredible amount of trust you need to put in Cloudflare, and the security of their systems.
Tailscale on the other hand has a service called funnel, which is a direct replacement to Cloudflare tunnels, however they differ in that Tailscale is a company with privacy and security as a priority and they accomplish the same goal as CF tunnels but their solution is designed to keep your data encrypted end to tend, from your client to your server. You therefore don’t need to place all that trust with Tailscale because they can’t see or modify your data even if they wanted to.
Both services accomplish the task of proxying public traffic to your backend server, however CF opens up all your data, and Tailscale doesn’t. Think of them both like a postal service, except Cloudflare opens up all your mail and puts it into new envelopes before giving it to the carrier for delivery to your mailbox. A lot of us prefer the postal service that just leaves your mail sealed from origin to destination.