FWIW the first serious startup I worked at chose not to do CE compliance (the EU governing body for electronic devices that may interfere with RF). Thus we did not sell our product to Europe.

Every single blog post had a set of people raging that we were assholes for doing this, but the reality was the cost of compliance just didn't make sense for the MVP. It was high 5 figures in cost which was just too much at the time. If we had achieved product market fit then the obvious move would have been to do that compliance to gain more customers, but we never quite got there.

I doubt GDPR gets to that level of cost, so the ROI looks a bit different. But I still think it's a reasonable decision to say "I simply won't do business in the EU because it costs more than I'll gain". A lot of companies also don't bother to go through the effort of printing the dual language labels required to sell their products in Canada, even though it's a decent sized market close to the US.

Tech, specifically the internet, has grown without regulation for a long time. But that era is over. These kind of decisions are routine in non-internet businesses where distribution, borders, and regulations exist. I suspect we're going to have to think a lot more about this in our work in the future.