Personally, I think a factor is there’s been a shift by companies in general to not make things as obvious to repair. My dad has a unibody 2012 MacBook Pro and the book literally tells you how to open it so you can service it by upgrading the RAM; a far cry from the situation today.
Older tools were held together with some common screws and were all built the same, so there wasn’t too much concern from the layman popping one open to clean it out to service it. Modern power tools just don’t look like you should be opening them, as the screws are completely hidden, they’re hard to open comparatively, and its usually the battery that goes anyway, which can’t be replaced when it’s been discontinued.
older tools were also much simpler, and usually clam shell halving. Modern tools have overmolding, overlapping clam shells, friction fits, screw posts, set posts. Clips, the single most hellishly thought up invention ever for fucks sake. And all kinds of voodoo magic electronic fuckery going on inside half the time.
