[ghaff]

I pretty much always wear business casual (which I find quite comfortable) on a plane. I don't know. I certainly wouldn't call someone out for wearing sweats or whatever (though I wish people wouldn't wear sandals). But business casual feels appropriate to me for the most part. Who knows? Maybe it gets me better treatment.

[johnisgood]

I have yet to find actually comfortable shoes for business casual.

[ghaff]

"Boating shoes" (e.g. Sperry's) were my goto when I went into an office. Though normally for travel I wear more of a walking shoe (or just trail shoes if I can be more casual). Allbirds are sort of a hipster fave and they are pretty comfortable. (For the plane I usually wear some very lightweight/compact shoe and have my walking shoe in my carry-on.)

But if you're talking a dressier leather shoe, they're generally not as comfortable--at least at the price levels I'm willing to pay. I do have a couple pairs with rubber soles. But I mostly don't need that dressy for travel any longer; business casual has slid a bit towards the casual side.

[NordSteve]

I’ve found that Clarks in their dress casual line are both comfy and business casual.