I think a lot of lessons learned around iPhone 2007-2012 have to do with looking at the elephant in the room.

Blackberry was doing great with keyboards and refused to sell more of. Windows Mobile had tons of muscles as market share they just trimmed off. Windows Phone had Marketplace trust issue that couldn't be solved. Nokia burned itself down before Google. Palm did most of it right, but couldn't be bothered with exclusivity reneg.

I can't say solving any one of them could have saved each of the brands, but they all had one giant elephant each that were enough to drag them down.