No, you provided a source that supports your narrative.
Here is a link that supports my position.
Do I need to register my business in the UK? Why and when is it necessary to register an enterprise with Companies House and HMRC?
www.hoxtonmix.com
It is one for the UK. Even though the UK is no longer in the EU it's laws on trading were active when they were in the EU and therefore the link I've provided it relevant to what was then and what it is now which is the following:
Do You Need to Register Your Small Business in the UK?
So, in general, any business in the UK must be registered if a trade or professional activity is carried out,
goods or services are bought or sold, income and profit are generated, and interest is earned. All this indicates that you are not doing a hobby, but a business.
Most often, small businesses are registered in the form of sole traders. In this case, the only thing you need is a national insurance number. The owners of such a business receive all profits after taxes but are fully responsible for all business processes. The
sole trader registration in the UK provides for the establishment of business owners as self-employed and the payment of all taxes.
So basically what this means is if you carry out a trade, goods or services are bought and sold, you MUST register as a business in the UK, even if you are a sole trader you must register as a sole trader.
This principle is common amongst other European countries as well.
So as I said, EU case law means squat. The individual country sets out it's law on trading, not the EU.