Hardware? Connected solutions? Content?
If there had to be one focus (Apple has proven it can work on several projects well), what do you think it should be?
Historically, Apple's major innovations have always and almost only ever been in packaging technologies for the mainstream. There was nothing inherently novel about any of the technologies in iPhone but the overall product was compelling, delightful, and approachable.
Fingerprint readers, voice assistants, and everything else have been done for years but Apple provided use-cases for them people could relate to.
I'd guess 95% of media thinks and uses the term "innovation" completely inaccurately and that's led to a lot of dumb products getting praise for being different even at the expense of being worse. True innovation makes experiences and life better.
That's where I think Apple has been focusing and will continue to focus.
Take AI for instance. Apple's been working on it quietly for years. They use it for everything from Siri suggestions to battery life optimizations at the silicon level. That's innovation.