Here's what happens when you defederate the entire internet, you'll be back on Reddit and users will be asking you "hey man why can't I talk to XYZ". This is literally what has happened to dozens of Mastodon instances already.
There are a lot of people on this ActivityPub thing who will block you for using the wrong software stack, block you because some old passed around list also had some domains that haven't been online in years, and the best part is they will never ask you before doing so. There's no way around this, other than running monolithic websites such as rdrama.net (which only work for one community).
They're literally speedrunning it on lemmy instances too, because on Reddit so many admins were used to "block everyone".