Gdp and tax are 2 different things.
Indeed they are.... but (all things being measured equal - i.e. no inflation, no changes in tax rates and a net migration level of zero) if the GDP of a country rises then the tax collected rises. That increased tax revenue can then either be spent so that spending per capita increases (hopefully) improving the quality of life or reducing the level of debt that the country is in (thus likely improving the quality of life for future generations). If the GDP of a country doesn't rise (or falls) then the only way to collect more tax is to increase the tax burden on the population of the country, which is less likely to improve the quality of life.
Tax collected will always likely rise during a time of high inflation, surely you realise this? By far the largest three contributors to the UK's tax income are Income tax, VAT and National Insurance
Inflation sees wages go up, thus income tax revenue rises (especially when the income tax bands are frozen as they have been in recent years).
Inflation also sees the cost of goods go up and therefore VAT receipts will rise (especially considering the huge rises in the cost of energy).
On top of those things we also had the large increase in employer and employee National Insurance contributions in recent times. Again more tax income.
Last up we've also seen the government increasing public spending in recent times to help prop up the weak GDP numbers. Again, this additional government investment (funded by borrowing) will also increase tax revenues (any government spend will result in a portion of tax being recouped).
Therefore, as you can see, these rises in tax income for the exchequer do not signify in any way a healthy economy.
The further recent hikes in tax levels (and lengthened band freezes) will continue to see tax income rise in the UK. It is however achieved at the expense of the personal wealth of the citizens of the UK.
Is it better for a nation when its ruling party is able to increase its tax revenue by increasing GDP? Or is it it better for a nation when its ruling party increase its tax revenue by a combination of making its people poorer while increasing borrowing thus likely making future generations poorer as well?