I think these two are two dimensions. You can have any combination of: a) single branch vs feature branches b) code review as a norm vs not required

(I'd rather draw a line with code review being/not being a norm, rather than whether it's mandatory. It can be mandatory and still shit.)

And as you suggest, I would expect that trunk-based development leads to greater care for quality. Add to that code reviews that seem to improve quality even further. I don't see a contradiction here.

Also, what the data suggests is that, for good productivity, it may be more important to have short lead times (from development to production) rather than just "no mandatory code reviews."

If you can expect code review to be done just-in-time, you retain the context, limit the tax of context switching, avoid Zeigarnik effect (https://en.wikipedia.org/wiki/Zeigarnik_effect), etc. So I guess this may be a sweet spot reconciling two sources.