Earn it, pay tax on it. Buy it, pay tax on it. Sell it, pay tax on it. Die, pay tax. It's all about handing over to government.
It's just a matter of time until banknotes are carrying tracking chips, because HMRC know they're unable to keep check on cash sales. Governing, regulating, managing. Thankfully I'll be dead by then.
That's it in a nutshell, isn't it?