I mean, yes of course they will over time just as with any piece of tech. Use a phone every day for years and not only will it collect cruft, but successive (and probably not optimised for older stuff) OS updates will take their toll.
I do wonder how the 7 year guarantee will actually work out in practice, especially now after (especially semi-private local) AI has become a thing. I think we'll probably be back in the early 2010's in that respect in that after probably three years your phone will start becoming very creaky, since the requirements for SLM's / MLM's will exponentially increase.