Enforcement in practice is almost certain to be "at the edge" with things like payment processors and ad networks that have direct business operations in the EU and are easy to demand third-party compliance from.
If you literally don't do any business with EU entities, even at arm's length, enforcement is going to be impractical and unlikely.
I also believe this. If you run a side project by yourself and you don't target EU users directly, but might have a few, it most likely won't be worth the effort to actually follow through on enforcement.
However, that seems like a very arbitrary line and governments love to waste money.
Ha. You’re insane if you think that the US Congress is going to start letting 28 agencies in the EU start fining small businesses that have no EU presence whatsoever. The political ads write themselves.
I have an answer: no way is the EU going to cut ties with the US over this, and no way is the US going to let the EU trample their national sovereignty by letting regulators start fining small businesses with no US presence because some EU citizen sent their data INTO the US. That’s ludicrous.
EDIT: you is the hypothetical you. If the EU targets you then they will use international law to do so.