Jack of all trades, but master of none?

I suppose it depends on my relation to the person, if I was hiring a personal chef I would probably go with master of one assuming what they were a master of was cooking and if I was hiring a handy man a jack of all trades would be fairly useful but I suppose that would make him a master of a different sort.

Neither. Pure specialists get pigeonholed. Pure generalists get discounted.

What's needed are people who are just generalist enough to collaborate well with people in other roles (and in a pinch, fill in for them) as well as deep expertise in one (or sometimes two) fields.

This is sometimes discussed as the need for "T-shaped individuals".

Another valuable approach is to specialize in two orthogonal things (typically one technical skill and one business domain) and master the intersection of these fields (it is best to be T-shaped in one of them, though).

... but oftentimes better than a master of one.

Is apparently a common variation/completion of the saying that I agree with.

Jack of all trades.

Synergy. Creativity. Versatility.