I would add that “barefoot” means, literally “barefoot”. I had convinced myself that “barefoot shoes” would be sufficiently the same because I was running outdoors and didn’t have the guts to do actual barefoot. I recently bought a new Assault AirRunner (curved motorless / manual treadmill) and run on it actually barefoot. The difference in my running form and sudden introduction of new muscle soreness makes clear how even barefoot shoes affect form.
Off-topic side note/rant: it is incredibly annoying how the Apple Watch becomes wildly inaccurate when on treadmills. GymKit has been out for years and has no - zero! - uptake among home treadmills and even shockingly low among commercial treadmills. And shame on Assault Fitness for creating an expensive, commercial level manual treadmills with an app that can see the data via Bluetooth from the treadmill, and failed to integrate HealthKit to sync the data. Wild decisions.