I don’t doubt that AMD and Intel are locked in a back and forth, BUT there’s no real direct competition between what Apple’s doing and what AMD/Intel are doing. For every Dell that’s like “create chips that can compete relatively well with Apple”, Intel or AMD would reply, “OK! We can do that by next year, but it won’t run any of your old software” to which they will likely hear “Oh, ok, then just keep giving us the same old stuff but faster?” THAT they can do.

And it’s not like Intel/AMD’s going to make a “special” chip JUST for Dell. Or, JUST for Lenovo. That HP system may be lacking in battery life due to poor efficiency, but it won’t materially affect sales because EVERY system will be lacking in battery life in exactly the same way! Luckily for Intel and AMD, Apple’s not out to hold the crown in single threaded or multithreaded benchmark performance, so one of them will ALWAYS be able to say “We have the best performing processor this quarter!”
AMD/Intel will make iterative slow steps to improve efficiency, but not threatening Apple, Apple will make iterative steps towards higher performance, but not threatening AMD/Intel.