if the increase in capital value was considered to be income (as it is)
Why are we even distinguishing between income and capital value if they’re both the same thing?
As it us, almost every firm of income from wealth is taxed less and enjoys more reliefs and allowances than income from work does. That is, straightforwardly, wrong.
An actual economist would go read about tax theory. Even, possibly, be aware of the bloke who gained his Nobel for explaining why we want to tax capital – and the income from capital – less than labour incomes.
But then that would mean knowing something about economics of course…..