Pensions are as safe as any form of investment (except leaving your money in cash), they are also the most tax efficient form of investment there is - at its most simple, your contributions are paid in gross of tax.
Generally speaking, if your employer offers any kind of pension arrangement to which they contribute, you should generally opt in.
I think the problems you are referring to were with Equitable Life and related to a very specific form of policy.
The longer someone leaves starting pensions saving, the less time their money has to generate any returns for them.
That said, there are other less tax efficient forms of investment which can generate higher returns (eg property speculation).
Your friend should talk to an Indepedent Financial Adviser who can look at their individual circumstances and work out what their attitude to risk is etc and advise what is appropriate for them.