They're not walkable because the are designed for cycling long distances in a day. Some find the eggbeater platform doesn't work for long distances because the platform isn't as big as SPD or SPD-SL pedals. Not everyone is planning on doing big daily mileage when touring so it depends on the rider.

notably the eggbeater with a platform (Candy series) pedal has much more surface area for a MTB style shoe to press on than the bare eggbeater, and is popular for touring.

https://www.crankbrothers.com/collections/candy

It's marketed and sold as a gravel/XC MTB pedal but has many other uses.

Yep, the Crankbrothers Mallett so I could also use the pedal in my other shoes. The shoe that broke wasn't durable enough but a Specialized one lasted the rest of the way. It was like a hiking shoe. I bought spare cleats at a shop once along the way but never needed them.

Flats are increasingly popular for touring as well. Turns out that unless you're trying to maximize efficiency at race levels, flats work pretty damn well. And even for racing, the value of clipless pedals is dubious compared to a decent-sized flat. I suppose weight weenies shy away because a decent flat is probably twice the weight of a decent clipless pedal. Deity black kats are 402 grams, whereas the most popular Shimano clipless pedal is 228 grams.

I do a lot of my touring and even bikepacking in vibram-soled sandals. Socks get so smelly even after a day or two that it's better to just go without them IMO.