Re: But has
The 'average person' isn't going to be ordering millions of pills for the NHS or pharmacies. Those people should already be well aware of the paperwork needed.. And as far as delays go, if we're importing, form-filling would mostly be the responsibility of the exporter. And most pharma companies in the UK and EU already export outside both, so would (should) be familiar with the process.
For small traders, it's something generally they'd only need to get right once, ie correctly declaring their products for export to the EU bloc. Customs brokers can assist if necessary. For individuals, it's a bit more complex, ie completing ATA Carnets for taking stuff to trade shows, concerts etc.. But again not really that difficult. Then again, EU changes to VAT haven't exactly made small trader's lives easy for trading within the EU.
The people getting it right will be behind the people getting in wrong in the large queue, as people are stupid, and if they can screw up, they will. Every design principle starts with removing the ways that people can screw up. https://ux.stackexchange.com/questions/30732/how-useful-is-this-coffee-cup-hot-contents-warning