Personally I do not anymore, especially for younger people. Lots of people who are 60+ stand by them but that was an entirely different economy and society than ours. It really feels like another billionaire's idea that doesn't really work in the long term. Infact, the person who came up with the idea of 401ks later regretted it and stopped putting into a 401k. I think that says a lot.
I'm in my 30s, I won't be able to take out a 401k until late 2050s. Who knows what the economy will be like then or if modern society will even be remotely the same as it is today. You're basically throwing money into a huge gamble. A gamble that is not looking good with current conditions. Wouldn't it be FAR better to pay off existing debt and just save more now?
The interest and employee matching is nice, which seems like everyone's main argument, but you also still get taxed a huge amount even if you take money out after 65. So it's not as great as it seems on paper.
Personally I just keep my money in my savings account and some CDs. It's low risk, helps offsets inflation, and I can use the money now if needed for emergencies.