I can almost imagine Apple unveiling a replaceable battery in the future and claiming it as ‘innovation’. It’l never happen but I’m sure they’d market it that way.
I would think they can at least do it for MacBooks. I mean I distinctly remember my MacBook from 2006 had a removable battery and just removing the battery exposed the storage and the memory. The price we paid was a slightly thicker MacBook so no MacBook air but I doubt anyone was complaining.
I think it is the other way round; thinness makes gadgets look good and feel light but more importantly, it provides an excuse to make everything non-replaceable on that altar in the underlying aim of planned obsolescence. Plus once you make it thin, you can always say that we can't go back because that is the new normal and making it thicker will be a regression.