I've been walking 4.5 miles a day, 5 days a week since Jan 2nd. As of today, I have lost ~53 pounds, gone from being pre-diabetic to normal levels, lost my entire wardrobe in the process, and finally my Vans died. They have been loyal a.f.
Glad they helped me on this journey to better health.
It's entirely possible to walk in a way that's not striking your heel against the ground, in which case a thin soled shoe is fine. I do all my walking, hiking, and running in very thin soled barefoot shoes and my knees are rarely sore or injured.
I've hiked 1000 miles of the AT over a 4 month window that way, and walk a few miles a day on sidewalks. I'm training for my first half marathon. My partner is an ultra runner who does 50 mile races in thin barefoot shoes.
You just have to slightly adjust how you step so your toes act more like a shock absorber. You want them to touch the ground about the same time as the heel or slightly before. I've heard it described as "fox walking". It's a little awkward but it is possible.
However, my only complaint about vans is just how super heavy they are. That would fatigue me so fast. If you can afford an upgrade or can find some used, I'd check out shoes from Xero. They last a good long time. The real sweetness is how they are super light. If you want a bit more cushion the Altra Lone Peak is also excellent.