They just farmed out the compute section of Nova Lake to TSMC which is a sad statement (probably a good business decision, though).
There is talk about the next version of Arc using 18a. If it does, I'd expect Intel to move that generation's compute tiles to 18a as well.
Apple farms out its displays to Samsung, a competitor. It's just how business is done.
Apple just recently moved back into the hardware space after farming everything out since the iMac gen2 days. Hell, I remember the Mac clones. I miss Power Computing.
Samsung's competition is Huawei, Xiaomi, Oppo, etc.