FfOS would have been a great alternative. I kinda still hope that a similar software setup (boot to browser, sandbox all the things to there) will one day be flashable to any generic handheld device, like older Android phones or the Pinephone.
In fact I use it daily in my 3310, buttons and all, as a replacement for my <model forgotten> FFOs phone from a few years back.
From that experience I can tell you it has nothing in common from the user point of view.
