If they're not paying for anything enough to keep things afloat (as their currency, government services, and now pensions are having a hard time doing right now...) it doesn't matter if they're there or not – they're just plundering the ship and crowding the lifeboats.
rich people are still very much net contributors. cutting the top tax rate will still leave them paying a high tax rate on a large income. if the choice is some super-rich people money and no super-rich people money it seems smart to choose "some".
Unless they're using more in public services/subsidies than they're contributing in taxes!
Think their university system, for example -- it's almost entirely subsidized by the government, but the generationally wealthy are by and large the biggest users of it, especially at Oxford and Cambridge. Not here to debate the merits of that system -- but the wealthy are objectively using disproportionality more of the services compared to the rest of the country.
Apply that across entire government sectors (healthcare, transit, pensions, real estate) and you have a government that, yes, while the wealthy are nominally paying the most, they're paying less into it than is sustainable for the amount they use it and expect it to function.
There's a whole separate debate about efficiency/"austerity", but "some" is not better than "none" if each of the "some" is a net-negative on the system.
do we know they are net receivers rather than net contributors? i would expect 30-something percent of the lifetime earnings of a very rich person to be more than the cost of putting that person through oxford? and do they really use more services around things like healthcare or less because they might lean on private insurance? seems like pensions are probably concentrated in lower classes as well. i'm not british though so you probably know of better data on this.
Government services need to be effective, not efficient. If increasing efficiency reduces effectiveness, as it sometimes does, then we're going to rapidly enter a cycle of "make it more efficient! The service doesn't meet our needs! It's costing too much for what we're getting! Make it more efficient!"
Many public services eventually get asked to be revenue neutral, which kills their value, which leads to people saying things like, "See! Public transit is a waste!"
