Sony did try connected ecosystems. They did it early, did it proprietary, did it wrong, and customers went elsewhere. They tried gluing everything together with MemoryStick and ATRAC. Everything, and I mean everything, had a MS slot: TVs, pens (!), CD players...whether it made sense or not. Anything that did audio pressured users to adopt ATRAC, with grudging allowance for MP3. MS was too pricy for anyone else to adopt, so it lost out to CompactFlash & SD. ATRAC was just inferior. Once those fell, Sony had nothing tying products together, and the walled garden went to weeds.
They lost sight of why ecosystem components are linked. Having gotten severely burned, they were shy to adapt and rebuild the necessary cross-platform infrastructure.