I work a corporate job and have taken advantage of employer matches for 16 years. It definitely adds up. I also never understood why people don't contribute to a 401k that offers matches. I also agree with you that it reduces your tax liability.
When I started out, I played with the contribution numbers and saw what my paycheck would be like with and without my contribution. It became a no brainer to me to contribute.
Now, I also want to invest more in real estate and I have all this money in my retirement accounts and it would be nice to be able to get access to that cash in a way that does not cause a big tax hit. The concept of buying and holding in a SDIRA might not make sense for me either. 401k's have other downsides. There are not great investment options(I don't like mutual funds), most employers screw you on fees, and there are proposals floating out there that 401k's over $3 million dollars get taxed in some way over and above 401k's under that number. I think a person should do both if possible because investors need to be diversified. It also depends on your style. Real estate is more hands on and allows for more leverage. Also, after 2008, aren't most stock investors institutional investors? I don't know if most people trust the stock market.