I wouldn't imagine just upping the vcore and the frequency clock will just magically make it faster and compete at the same level as an intel chip.
I'm deeply skeptical as a developer, you -will- get compiler errors, and it's going to suck for a while.
Isn’t this the exact concept of the VAG EA888 motor used in the Audi A4 and extended all the way up to the S3?
That said, the rumored chip is an actively cooled 12 core 5nm part which is more like an RS3 motor with extra cores/ cylinders
Having said that, I think the top requirement for most laptops is that "it's gotta run what I need it to run on day one".
For a huge amount of light users, ARM Macs are going to satisfy that requirement easily.
Once you move up the food chain to users with more complicated requirements, however, it's less of a slam dunk... for the moment.
I guess its all trust that Apple can pull it off and there's no detailed rumors yet?