Good attempts have been made but it's quite difficult, especially considering what most people expect now. New phone releases simply won't live up to those made by producers with a lot more experience, resources, and IP.

The best concept I can imagine is a custom GNU/Linux OS with an Android compatibility layer. But even that won't be as smooth as what many demand. That's the only way I see to make a phone without being beholden to Apple and Google decisions. Purism had a good concept but it ended up being a disaster. Pine64 has a developer phone but the hardware has low specs (meant for devs).