From the comments:
There is a potential saving for some rather than simply a time deferral.
Many people will get a tax “rate” saving. For example, gain tax relief on their pension contribution at 40% but then have their pension taxed later at basic rate, etc. Ie, few people actually earn more retired than when they are working.
Intuitionally – to coin a horrible word – I don’t think so.
Say the tax rate saving is 20%, as above. OK.
So, I put £100 into my pension now. That grows at 5% a year (yeah, I know, har har) for 20 years. Without compounding that gives me £200. I then get 5% a year off that for 20 years of retirement.
I get £200 in income and pay £40 in tax on it.
My tax saving when I put the £100 in was £20.
Maybe this particular example doesn’t actually show it, or it does, whatever. But there’s definitely some combination of investment returns, lifespan and tax rates which shows me paying more tax by having pensions deferment than not.