Brexit
The EU wants to force the UK
This is where the problem with sovereignty comes in. The EU is not doing this, the UK is free to adopt its own terms for the interaction it has with other countries. But when it agrees trade deals with those countries it negotiates a set of common terms, which it agrees to abide by.
I agree that some of it could be interpreted as political issues, but they all have affects on trade. Trade deals are very complex because they involve all the ramifications of various standards, regulations, state aid etc.
There is a particular problem evidenced in this negotiation caused by the hostile dishonest, caniving approach by one party, the UK. As a result there is very little trust and the EU, understandably wants every term legally binding. Particularly while the UK government states that it seeks to diverge from the terms when expedient to its own interests.
As one commentator said today, the level playing field is only problematic to a country which intends to lower standards, to deregulate, to diverge. If that country was intending to maintain high standards maintain good regulations and be cooperative with its partners, the level playing field would be no problem at all. There is a sliding scale here which has implications for trade.