Interesting, when I was working on getting UL and CSA certifications for some equipment we were importing from Europe, I was told CE was a self certification, I had no idea it required ISO9001. That right there is reason enough not to sell to Europe unless you will be getting a huge increase in sales.Throw into the mix, the need being CE marked in the EU. In order to CE mark a product, you have to have a quality system, e.g. ISO9000 for example , in place and the products need to be tested and approved by certified agencies. No small business is going to jump through those hoops.
It took the company I worked for 25 years ago the better part of a year and well over $100K to get our ISO9001 certification and many thousands to run through the testing/certification process for each product.
Since Brexit, I don't know if the UK a still requiring CE marking but more than likely it is.