I had always thought it was a nerve impingement issue partly because it felt like really painful pins and needles like if your foot falls asleep.
I’ve been cycling to varying degrees now for about a decade and it seems like only the last two years really has it been an issue. Same bike same shoes, etc. I wouldn’t say I’m in grossly worse or better shape either.
I do have a tendency to wear out the outside edges of my shoes when walking so maybe it’s more of a shoe issue than I ever thought. I may try out those bikefit wedges, it’s at least a cheap solution to try before I go down the road of buying different shoes, saddles, paying for a bike fit, etc.