No one said they were but from now on (outside of the very 'best') they'll become auxillery to any high-end technical games and there's a "world of difference" between the latest Xbox/PS hardware and something else like the Switch/Steam Deck since support for the latter by AAA game developers wasn't really taken in any serious capacity for extended periods ...No, integrated graphics are not going away at any point in the hypothetical future.
The "hardware convergence movement" that nearly everyone else so desired here between console and PC platforms ultimately means that any unlike systems will be eventually driven off to the cliff of extinction since it's industry consensus to move to ever more powerful/capable hardware and much of the future of ultraportable devices won't be looking so good ...