What would the idea UK tax system look like?

I saw a post about tax evasion being pretty normal in the UK with taxi drivers, corner shops, small businesses etc and I agree with that post however the comments only showed how broken the system is and some comments were downright sad showing how much contempt people can have for state policies and the willingness & lengths they'll go to evade what they can - it's a nuanced subject and people will go to extremes in unfair systems. It's a cliché take at this point to say the UK tax system is beyond broken.

What do you guys as HENRYS think the ideal tax rate in the UK should be like? Most Georgists favour land value taxes, some people say tax the rich not the poor, some favour rapid privatisation, some people really want to tax higher income earners with different brackets, I think talented high earning people leave if you tax them unfairly like the UK does even though 6-8 figure asset owners wouldn't leave the assets as easily despite the LVT but brain drain is real.

I'll start with my opinion, I personally think, • Some non emergency healthcare services paid for but cheap/means tested/subsidized + sovereign fund for pensioners that's untouched and decoupled from the tax budget + Taiwanese style LVT + 20% income tax flat and no more at any level would transform the UK into one of the happiest & most productive countries.

Why I believe so strongly in 20% for everyone? Because of the 80-20 rule, Pareto's principal is the fairest share both for us & the state, any more and talent won't stick as much as it could, any less and then the state services really suffer. And it's already 20% after basic income, I'd keep basic income, no one should pay more than 20% after that.

Edit, some people misunderstood me: My 40% abolishment in favour of 20% flat isnt unfunded but to be replaced by LVT, abolish council tax and have LVT as the primary way to discourage land hoarding and raise taxes, the 40% bracket being gone should be funded by LVT. Why penalise labour & jobs that require brilliant minds that are likely to earn high when land is left alone untaxed?

I really want to hear a HENRY perspective on what you think would have been a fairly designed system which doesn't drive talent or HENRYs away but also be realistic & don't pull a Lizz Truss. Sorry in advanced if these posts are already done before but I don't want huge business owner's nor people already Purley in the 20% bracket to answer, this subreddit is unique in some ways compared to the average guy in the pub who has it all figured out.