Dipping my toe into this thread is like learning to swim in a piranha tank but that is a fairly simplistic statement that does more harm than good.
I operated (and still have) a company like that from my time as a software contractor and it wasn't for tax avoidance purposes. I paid tax via the company in corporation tax, I paid VAT via the company on things I bought to run the company, I charged VAT too but i operated on very little outgoings as I didn't need to buy supplies etc so it was negligable benefit to me), I paid tax on anything I took out of the business to me personally.
A really rough comparison on an "income" of 100K (makes the figures easier) - I exclude VAT as in most case what I charged wasn't offset by what I bought and it went straight into my VAT payments.
1. From that 100K I pay my expenses (business banking fees, accountant, filing charges, regus workplace etc) of about 3.5K, PAYE my tax free allowance of 12,570, I then pay the low rate of corporation tax (19%) on the remainder which leaves a company profit of just under 68K - I than pay 33% tax on that to take it out as a dividend leaving me with with a "take home" of 58K (remainder plus PAYE) - of course there is more detail in what is paid out around having pensions, etc but that's the gist of it.
2. If I earned 100K PAYE after deduction my take home would be 68.5K (using an online calculator) but this is not taking into account pensions etc so depending on your contribution level you could be shaving a few thousand of this figure.
My reasons for it were not to make more money, it was that I wanted to have more say in what types of work I was doing and for who and when I worked. Also the vast majority of companies that wanted my services just couldn't pay individuals for short term contract work without that individual becoming employees of the company and am I going to become an employee of that company for 4-8 works of work and then move to become an employee elsewhere again and again with all the tax admin of constant job changes. Especially if I was fulfilling one small aspect of a much larger project as a sub contractor for a larger development firm in parallel to other work.
Covid increased this by the fact we were forced to work remotely and I could work for companies that previously I wouldn't have entertained due to location (and those companies could attract talent they wouldn't have been able to before). Covid actually started to put pressure on the contract rates as surely working from home meant I had less expenses and could afford to be paid less (and that still hasn't recovered in some sections).
They recently (and poorly) attempted to make this more stringent with implied employment rules so in a lot of cases there is almost no difference in being employed or contracted for purposes of how much tax is paid for a large portion of those using the system.
Do I think HMRC make just about everything more complex than it needs to be, definitely, and I truly think that the system is not set up to be fair to the majority of people in comparison to the top minority (a tax of wealth would benefit everyone if done right).
But to label a currently legal method of operation as en-masse "tax avoidance" is not a true representation of the situation for the vast amount of people doing it.
I do allow for the fact that in any system there will be people using the system for illegal gains but that is what the enforcement elements of the tax service are there for - to ensure that the current law is applied correctly and punish those that don't pay what they owe correctly.
Please be gentle in your responses (I am still a politics thread newbie)....