It's the other way around, it's down to GrapheneOS to support other hardware. They simply choose to focus on Pixels.
You're onto something with the AirTags but you haven't got it quite right. Every Apple device participates in the Find My network, which means any Apple device marked as lost will have its location reported, anonymously, by every other Apple device it can communicate with. This is a good thing, unless you're being stalked via an AirTag placed on your person, but Apple has taken pains to mitigate this issue. One shoe company recently released shoes with AirTag compartments so parents could track their kids, and the placement should mitigate the beeping they can emit. Honestly the AirTags and Find My network do more good than harm, the impact to devices participating in the Find My network is minimal, and if it's your device that's lost, you don't want people opting out so thieves can get away with stealing your stuff.
Nice — I absolutely use SponsorBlock on desktop (/laptop). Did not know it was on mobile.