This is much harder to evade - if you own most of Mayfair, you can't just move your assets elsewhere - they are very clearly tied to the location.
Of course, this would mean taxing powerful aristocrats, including the royal family. With their large majority, the British government had the opportunity to do this, but decided to take an easier path. The reason why this path was easier is now becoming clear to them.
Then there are the semi-elective things like healthcare, education, home security. These kinda dont work for the whole society. The rich are thus paying for their own out of pocket. But they are also paying for the semi-working system for everyone else.
I think introducing a wealth tax just to balance the books without rethinking who and how accesses public funds, will just end with the rich leaving. Some may say good riddance, but the UK budget is now beyond creaking and heading for collapse.
Oh and when I say "the rich", that probably covers many people here. IIRC earning 90k per year puts you in the top 1%. A 10-15 year experience NHS doctor is in that bracket.
The very top sliver who own the majority of the land and assets and who never need to work a day in their life are who must be looked at; that hereditary wealth needs to begin to find itself flowing into public services more and more.