Then they'll try to come back... after their EU user-base was kicked out and forced to find alternatives.
If the original business couldn’t, its unlikely the competitor could.
I know in my business I’m shutting off EU sales.
Considering amount of FUD spread about fines, even here, with fairly educated readership - I don't think you can really trust other people's cost / benefit analysis, even when they happen to have same variables with same values.
People are often wrong even in much clearer cases . . .