Yes, argument does screen off authority. But that's no reason to knock "life experience". ... Learning anything is a personal experience, which colors your other beliefs. ... A more fruitful goal is to repair your interlocutor's argument, to acknowledge how their personal experience has led them to having whatever beliefs they have, and expose symmetrically what elements in your own experience lead you to different views.

I agree with your point and your recommendation. Life experiences can provide evidence, and they can also be an excuse to avoid providing arguments. You need to distinguish which one it is when someone brings it up. Usually, if it is valid evidence, the other person should be able to articulate which insight a life experience would provide to you, if you were to have it, even if they can't pass the experience directly to your mind.

I remember arguing with a family member about a matter of policy (for obvious reasons I won't say what), and when she couldn't seem to defend her position, she said, "Well, when you have kids, you'll see my side." Yet, from context, it seems she could have, more helpfully, said, "Well, when you have kids, you'll be much more risk-averse, and therefore see why I prefer to keep the system as is" and then we could have gone on to reasons about why one or the other system is risky.

In another case (this time an email exchange on the issue of pricing carbon emissions), someone said I would "get" his point if I would just read the famous Coase paper on externalities. While I hadn't read it, I was familiar with the arguments in it, and ~99% sure my position accounted for its points, so I kept pressing him to tell me which insight I didn't fully appreciate. Thankfully, such probing led him to erroneously state what he thought was my opinion, and when I mentioned this, he decided it wouldn't change my opinion.