The ARM comparison in terms of power efficiency doesn't really make sense, does it? I guess he's right about the efficiency but there isn't a real competitive ARM-based laptop available right now, at least I haven't heard of one and even if there is one: Apple couldn't just go for ARM they'd have to adapt their OS for that and I assume by now there is a lot of code in there making use of x86 quirks not easily adaptab…
The transition will be harder for third party devs, but there having been popular ARM Apple platforms for over a decade will speed things up considerably. Many Mac apps will have ARM versions available overnight.