"Literally something that should not exist" is the perfect way of putting it. In 1990, lots of people needed boutique workstation vendors. In 2000, nobody did.
Apple abandoned both intel and Nvidia (not to mention AMD/ATI) which is interesting. Apple seems to be vertically integrated like IBM or SGI - but better at differentiation and at locking in new customers.
Apple seems particularly good at differentiated product design; their devices often just look better than the competition and seem to offer a better user experience.
(That being said, SGI's designs look pretty cool too.)
This is conventional wisdom (and thus, usually correct).
However, it's always interesting to look at counterexamples: Beretta, for example (in business for 500 years).
https://www.albertcory.io/lets-do-have-hindsight
or the IBM PC, which cannibalized IBM's business, at least in IBM's mind. Thus, they screwed it up and let Wintel make the real billions. So it worked, until they took your advice and decided that had to stop.
Is there any significance really to Foot Locker basically being a reorganized Woolworth's as opposed to being a brand-new company?
If you're big enough and have some product lines that still bring in a lot of money and didn't totally collapse like IBM you can sometimes pull it off. But it's hard.