"'Investing in property ' is mostly to obtain value for the property owner, either through renting it or buying in an area where it is likely to appreciate in value. Speculation again. there is the acquisition of more wealth, of course by way of dividends.
Businesses are mostly financed by bank loans, not by wealthy individuals (and yes, I do know about Angel investors)
As for taxation, it is at a much lower rate than taxation on earned income. And there are lots of ways it can be avoided."
Speculation works both ways, many shares dont appreciate greatly, you probably have a private pension, the growth that pays your pension depends on buying and selling shares.
Property is to be taxed at a higher rate than earned income, most is finance by loans any income is taxed, any capital growth is taxed, if you own it on death its taxed. I agree taxation should be higher, but the higher the tax the less incentive to invest. Governments want wealth invested, not sitting on a deposit account, so has to give an incentive to grow.
There are many concessions allowed for business expenses these regularly change according to government policy. Business are a risk and many fail or make less money than employment, companies large and small go bankrupt often shares are worthless