You can buy phones with non-embedded batteries but they suck. That's not a coincidence.

What is your hypothesis for why more phones arent designed with non-embedded, directly replacable batteries? If it's such a highly valued trait in a phone, why doesnt some company just gobble up that market share? Why havent existing solutions sold well? Mine is that consumers dont actually value non-embedded batteries when accounting for all the tradeoffs. What's your hypothesis?

They were given the choice years ago, when some Android phones had removable batteries and touted that as a feature. Nobody seemed to care.

In contrast, users were also given the choice between headphone jack and Bluetooth for years when every phone had both, and clearly chose the jack. BT headphones were rare. But Apple and many other phonemakers figured out they make more money by removing it.