As someone who is certified in Advanced Tax Law, I heartily recommend that everyone get a retirement savings account. You actually get a DOUBLE tax break, if you contribute to a retirement savings account, since it counts as a tax credit and an adjustment to gross income. Score!
If your income is under a certain (low) level, contributing to retirement savings also counts as a tax deduction. So that's like a triple tax break! This is rather rare, because most people who are that level of poor don't contribute that much to retirement.
I'm more or less forced to open my own retirement savings account, since none of my jobs provide one. But I'm totally not qualified to play the stock market for forty years and make enough money to retire. So I'm doing the "put all my eggs in different baskets" strategy. Instead of buying stocks, I'm buying mutual funds. And instead of buying one mutual fund, I'm buying twenty. One of those investment expert teams has to give more money back than I would get, if I did stock market trading on my own.
Hopefully, in forty years, I won't look back on this decision and want to slap my younger self.