I noticed this also sometime ago, my go to heel height for comfort and all day wear is 4.5" , which is high for my size 5uk foot, but it feels so natural. Oddly i was wearing my 4" wedge heel boots recently and they almost felt like i was wearing flats (strange phenomenon 🤣). 5" heels without platform is my upper limit, can only wear those for a few hours. The 4.5" arch is the sweet spot for me 😁