It's a fact that (at least in the EU where I live) the majority of tax burden ends up on small companies - mom & pop shops, little bakeries etc. Who simply can't afford these global tax avoidance tricks (or can't use them because they're "local")
Not that this is wrong or right, just a fact you can't argue with. I run a small software shop in the EU (4 ppl) I know what I'm talking about.
As I said the UK setup is mostly used for self-employment, so when you need a team mate they are most likely incorporated as well (either in Poland or the UK), so you just sign a B2B contract.
> The European Single Market, Internal Market or Common Market is a single market which seeks to guarantee the free movement of goods, capital, services, and labour – the "four freedoms" – within the European Union (EU). https://en.m.wikipedia.org/wiki/European_Single_Market
If you don't mind travelling then you can, very cheaply, pay very little to no tax being a small company. In many countries it is legal to do so.
When the EU told Ireland to stop this behaviour, Apple was pushed to declare a location for that stateless company; they picked one of the UK Channel Islands, a crown dependency with no taxes, and started funneling money through that. In the process, they got another special deal from the Irish government to keep a chunk of "IP ownership capital" on the island, which resulted in a much lower rate of tax on that money than they would have otherwise had to pay (but ever-so-slightly higher than if they had just put everything in Guernsey, so they could save a bit of face).