These days whether the employer contributes to a pension fund, or simply gives you the money and lets you do your own investing makes little difference.
There might be certain tax advantages to one or the other, but the point I'm making is that if your projected retirement income is inadequate, the only person who can do something about it is you.
The days of "Work for us for life and we'll pay you for the rest of your life" are over. It was based on investment returns and tax advantages that just don't exist any more.
Actually, I prefer cash purchase. At least I know that what's in my hot little hand is mine and that's that.
Ask the retirrees from United what happens when you have a company pension, and then the company goes south!!