You can leave your unused drawdown pot but it might be taxed on the beneficiary after the age of 75 depending on how they withdraw it and what tax rate they pay.
It’s an interesting one this, and whilst you can guarantee pots with annuities and provide for a spouse if you wish, many people still prefer drawdown for the death benefits they provide.
That shouldn’t be the reason for deciding on drawdown though for me except in a few circumstances. When you start saving into a pension, your objective isn’t to leave it behind for other people. It’s to build up a pot to enjoy your retirement. I think some people lose sight of what they saved for in the first place. Ideally you should spend every penny of your pension pot before you die. Maybe leave enough for a spouse but they should then spend it. The only exception I would say are people who have other savings/investments and an IHT liability. In these situations, the pension wrapper is a useful IHT shelter and it is often better to use other sources first.
In my experience, many people tend to over save and under spend, as the fear of the rainy day is always there. However, time really does tend to catch up with people and spending drops as you get older. The nightmare of care home fees is always looming large though.