Comparing retirement savings to ordinary investment is not an apples-to-apples comparison - retirement savings are savings for retirement - if you want to invest in things now and live off of (or reinvest) those earnings, then retirement accounts are not the right vehicle.
That said, here are some benefits of the main types of retirement accounts:
Benefits of a 401(k):
- Employer match - you get an instant 100% return on your contribution (or whatever the match is)
- Tax-deferred savings - you don't pay tax until you withdraw from the account
Benefits of a tratitional IRA:
- Tax-deferred savings - same as above
Benefits of a ROTH 401(k):
- Employer match - same as above
- Tax-free growth - you only pay tax on what you contribute (since contributions are after-tax) - you pay no tax when you withdraw from the account
Benefits of a ROTH IRA:
- Tax-free growth - same as above
(the benefits above are not exhaustive, there are other benefits such as using a ROTH IRA for higher ed. expenses, etc. but those are the highlights)
If you have a plan for how you hope to use the money now rather than later does it make sense to hold onto it?
If your plan is meant to provide income at retirement, and earns returns higher than the returns plus matches and tax benefits you get from retirement accounts, then yes, it may make more sense, but those benefits are generally very hard to beat. Plus, having the money locked away in an account that is painful to tap can be a good thing - you're less tempted to use that money for foolish decisions (which everyone makes at some point).