Indeed. Everyone is encouraged and /or forced to spend money. If people have money/savings, it gives them freedom as you say. People need to be on bended knee. Its the same philosophy for politicians as it is for company bosses. The Scandanavian commercial director I once knew told me as such. Said he encourages his sales people to live it large in their personal lives at every opportunity because "it keeps them hungry".OP
It's not just about tax, it's the notion that nobody should have the freedom that saving money gives you.
The 1970s taxes like CGT were from a time of high inflation and socialist fantasies. If it is harder for people to save money, which is how all capital is made, then you are left with 2 options, you must borrow what you need from a bank or look to the state for handouts.
That gives too much power to banks and politicians, as we have seen the cost of that in 2008-10.
All taxes were increased for 2 world wars, and all customs duties are based on medieval-era protection rackets.