Apple

Because a big portion of ARM's other revenue Apple has set up the foundations for. They set the foundations for ARM on mobile devices with Newton - then perfected it with iPhone, iPad, Apple Watch, etc. Then, in an industry-defining shift, Apple became the first major player in the industry to successfully push ARM onto Laptops/Desktops and have any sort of market for doing so.

ARM is going to be just fine - the only viable alternative is RISC V which as it stands is immature and not very usable. Giving Apple a break on royalties is a sensible option if Apple is creating a ton of new business - which they are. Apple revitalizing ARM on desktop/laptop is creating a ton of new business as competitors do what they always do and look to copy Apple.