I've seen several laptops start out in the 90-95% SoH range, drop off quickly to the mid-80s and stay there for a very long time. Similarly for iPhone batteries, they go below 90% pretty fast, then each % off takes longer and longer until they actually start dying. Maybe that's due to different baselines though, BMS of laptop batteries normally refer last-full energy to the design energy, which is probably just a fixed value in an EEPROM and might not ever be reached due to a more conservative charge cutoff and tolerances.