Plenty who received furlough were also
taxpayers. And plenty of that furlough money was spent and went back into the economy.
The foundation of the economy is producing, not spending.
If those people had not been in furlough, their work during that time would have resulted in £x amount of value produced, eg windows fitted, plumbing fixed, coffees sold.
They would get money to represent the value of that work, which they could swap for other people's work (including food farmed, electricity generated etc).
Instead, they got the things other people made (food, electricity) without producing anything themselves.
So everyone has to work a bit more now and get nothing in return, to make up for the furloughed people receiving the value of that work for free 5 years earlier.
The way the government did it was to print money. But money just represents work done. The mechanism is that the printed money is used to buy some 'work output' now, but then the resulting inflation reduces the value of the money so later people get less for the same work.
In the end, money is just a way of exchanging work that is done - and in furlough people were given money to buy people's work without exchanging it for their own. So we all have to give some work without getting anything for it ourselves.
That doesn't mean furlough was wrong. Without it, companies would have gone out of business which would have hugely reduced people's ability to work and create value. Then they would again be given the value of other people's work without doing any work in return- in benefits - possibly even more than furlough.