Just to clarify: ferrite doesn't much care how it's gapped, just that flux density amplitude is reasonable for whatever power dissipation is allowed.
Where it does matter, is the winding and what wire is used. The fringing field around the gap is extremely aggressive, inducing eddy currents even in fairly fine wire.
Typically, the center limb of a shape core is cut short, leaving an internal air gap. The width of this gap is the total air gap in the core, all other core faces are flush. This is typically a sizable amount, 1mm say, so the fringing field extends quite far, enough that a simple straight bobbin won't save you.
Bobbins can be specially constructed to maximize distance between inhomogeneous fields and the windings, and the windings themselves (proximity effect), to minimize copper losses. These are easily made in these days of 3D printing, but I haven't seen any used in production at least yet (but I also don't take apart a lot of stuff anymore these days, so that's not a great reference!).
The alternative is to use extremely fine wire, which is cost-prohibitive, but hey, if you have some on hand, you absolutely can do it, you'll also get reduced ACR in general for even higher efficiency overall.
There is no reasonable way to gap a toroid; ferrite toroids are, to my knowledge, never gapped in any production-adjacent context, for purposes of distributing air gaps (exceptions for very specific circumstances, like Hall effect sensors -- but that's not for distributing air gaps or reducing losses). You could fracture or cut a toroid into a bunch of arc segments and gap them individually, and the fringing field around each gap can be smaller than the wire diameter wrapped over it (bonus points for adding a layer of spacer tape over the gaps, to increase that distance).
Heh, I've even had a toroid do this to me, automatically. When pulse testing one, which might've been NiZn material for what it's worth, as I swept frequency, at one range it seemed to do something a bit different, and going back over it again more slowly, tick, and suddenly the inductance was much lower. I poked at it, and the core fell apart in the winding: ten or so fragments of very regular size. Apparently I had hit an acoustic resonance, excited by magnetostriction, driven by the unidirectional pulses I was using. Not that I would recommend cutting ferrites in this way.
So yeah, powder cores are desirable where the size and shape of a toroid is, at least not detrimental, but perhaps even preferential; and where copper losses are best avoided, while remaining economical. Gapped ferrite shapes tend to give more compactness at higher frequencies, but tend to be more expensive.
A common strategy is to avoid the issue entirely: use the best of both worlds. A typical DC-DC module might be an active clamped forward converter, using a planar ferrite transformer (a transformer has maximized inductance, zero air gap) and either a planar gapped ferrite inductor (in a planar winding, the wiring can be relatively far from the gap, and can also be customized on every layer), or a composite molded inductor (like toroids, these use powdered metals, but achieve higher density and lower cost while maintaining high Q).
Tim