Taxes pay for:-
Having properly tarmacked roads running all over the country, linking towns and cities; and those roads being marked out with white lines and there being regulation of which side of the road you drive. I'm not sure that such things could be achieved by asking private companies to tender for the right to earn a living from their provision.
Having armed forces to protect our population from foreign invaders. I'm not sure that private armies would fnd it easy to makea living from such provision.
Having health care available for all, free at the point of use.
Having people cleaning the streets, taking away and disposing of waste, maintaining highways and public open spaces.
Providing education for all children.
The list goes on.....
There are people who are wealthy enough to decide that they woydbe happy to pay for their own private roads (I don't know where they would go to), bodyguards, personal physicians, private tutors, and so on.
The list goes on.....
I personally prefer to be taxed rather than to be expected to pay for everything myself. We've moved on since the days of primitive hunter/gatherers, wandering tribes, warlords, Lords and serfs, The list goes on.....