You are very naive.
I'll tell you about there players in the modern era, all leading internationals with very many caps, who earned millions a year each. Probably £10m per annum each, as a minimum.
One had to go to his club and ask for an advance on his wages, as he needed to settle gambling debts. He'd not only gambled away money he had, but owed a seven figure sum he didn't have.
The other cut a deal with a journalist that he (the journalist) could have an exclusive as long as he didn't report a story about how much he'd gambled away (well into seven figures) as his wife had threatened to leave him over his gambling habit. In the end, they agreed a compromise, reporting he'd lost a small fraction of the amount he'd actually lost, and the journalist got his exclusive.
The third had to remortgage his house a number of times to raise the money to settle gambling debts. A man who shouldn't have needed a mortgage at all.