For single core workloads, probably. Didn’t we hit the clock speed cap around 2010?

Building a project isn't a single-core workload usually, though.

Isn't C++ compilation mostly single-core-bound still? Of course it does compile as many files in parallel as there are cores, but it's not possible to compile a single file in multiple threads.

Yeah but most projects that have compile times long enough to care about have many source files.

You haven't seen most Android projects that have a massive legacy module that Gradle spends 5 minutes compiling and doing nothing else. Seeing those 7 lines say IDLE is a daily experience

There is a lot more in single core performance then just clock speed, in fact ipc is even more important then clock speed when it comes to single core computing

Not surprising as Moore's law had stopped applying to CPU. Assuming each year CPU gets 20% improvement, from 2012 to 2021 the latest cpu is 5x more powerful than the old one. Considering 30% performance loss for converting x86 instructions to ARM, 4x is a reasonable number.