The 401 (k) is simply objectively better. Both 401 (k) plans and IRAs have valuable tax benefits, and you can contribute to both at the same time. The main difference between 401 (k) and IRAs is that employers offer 401 (k) plans, but people open them (using brokers or banks). IRAs tend to offer more investments; 401 (k) allow for higher annual contributions.
But despite how positive all of this is, there are good reasons to have an IRA in addition to your 401 (k). An IRA not only gives you the ability to save even more, but it can also give you more investment options than you have in your employer-sponsored plan. And if you have a Roth IRA, there's also a chance to earn tax-free income in the future. Whether a 401 (k) or IRA is better for a person depends on the person.
A 401 (k) plan allows you to contribute more money each year before taxes than an IRA. However, an IRA tends to have more investment options, allowing for greater control and flexibility over the account. Keep in mind that a person can have both. A 401 (k) is a better option than an IRA if you want to invest more for retirement and aren't too picky about investment options.
Most plans are limited to the securities (such as stocks and bonds) chosen by the employer.