The costs may be large and many companies may leave, but China has shuttered out these same companies and they've done well to solve their needs from within the country.
Of course China's goals were much different than citizen's rights.
We really need something like the GDPR, and it can't be opt out. There is far too cavalier an attitude by almost all businesses toward your information and they never really suffer any penalty for their recklessness. And there are quite a few genuine bad actors who really need to get reined in.
I also hope that once the GDPR is in effect, there will be some adjustments to it when everybody starts figuring out what works, what doesn't, and what's expensive.
However, the GDPR probably should have had some sort of "grandfather" clause that would have applied to something like Ragnarok Online. Bringing a code base of that age into compliance would probably require a massive engineering effort that completely swamps the revenue they are currently getting.