UI latency, the entire point of a device, is a single threaded use case. Multithreaded performance is only good when you don't care about power use, but that's

UI latency, the entire point of a device, is a single threaded use case. Multithreaded performance is only good when you don't care about power use, but that's never true on a battery powered phone. It's actually more often the case that you optimize software by removing accidental excess concurrency than by adding it. Junior engineers love them some unstructured concurrency.