Insurance companies are guaranteed to take a large percentage of your pension. Plus when you die, they get most of the rest. You can't pass it all (YOUR MONEY) to your beneficiaries. This is 100% risk to pension holders.
Simple, you hold risky investments early in retirement, and over time (average retirement is 20 years) you move the investments to LOW risk types.
Forcing annuities on everyone is more nanny state nonsense. If people want to buy annuities, fine let them. Just don't force it on everyone else.
The risk is whether or not you will die before your pension fund runs out. And have to live entirely on the state pension, which is very low. Which would depend on the size of your fund whether you have an additional source of income (or other forms of wealth such as property that you can use for income), and your life expectancy (which most people underestimate).
Also, there are now annuities which will allow you to pass money to beneficiaries if you die before 75, but you sacrifice income.
The rules may very well change, anyway, as lots of people agree with you. The gov't and insurance companies have been looking at drawdown-y products for middle income people.
ETA: The risk to the insurance company is that you will live longer than they expect and they will end up paying you more than you gave them in the first place.