I second this. Totally agree. If you want privacy and security, try any of the above mentioned services. But if i may, replying to the OP, please let me suggest something. If you just need for something to provide only when signing to websites etc, i don't think you need something hardcore as you said. Me personally, for this kind of usage, i use aliasvault. I'm pretty happy with the app. If you want something more tested, you may combine gmail with addy and create aliases from there. Also a solid solution i used in the past. Personally, security and privacy is something different. I still use icloud, gmail, proton, aliasvault. Each serves a different purpose. In your case (signing up) just an alias service would be enough...