I agree that some woods are not suitable for use as dowels (unless the dowel barrel itself is a part of the visual design, rather than being buried in a joint). That said, I use a jig of my own make to manufacture dowels of every size, from almost any wood. The key component is a dowel plane blade made from two pieces of tool steel welded together at a roughly 30
o angle, to form a winged cutter (and then hardened, ground and honed to chisel sharp). That goes on a simple wooden form with a hole to guide and form the dowel. I use it to make dowels of any size from 1/8" diameter up to 3/4 diameter, and pretty much any length that the diameter of the wood will support, in almost any wood - as long as, as Andrew says, it is straight grained enough to eliminate runout of the grain over pretty much the length of the dowel that you want turn.
Setup is simple: Drill a guide hole the diameter of the dowel you want (or maybe 1/64 to 1/32" over) near the edge of 1" stock (hard maple is a good choice, but anything reasonably hard will work, and I get great results with walnut), and taper the input side of the hole with tapered countersink. Sand down the side of the piece to the hole on a stationary belt or disc sander, or whatever works for you, so that you've got a small gap in the barrel of the hole exposed. Generally helps the turning process if you sand a little deeper on the exit side than on the input side. Clamp the blade on the resulting slot, with the wing toward the input side. Maybe dab a little wax into the hole to lubricate the cuts.
To use: Cut square stock 1/16" - 1/8" bigger than the diameter of the dowel you want. Chuck it in a drill and sand a bevel on the leading end. Feed it through the jig at whatever speed works for the material you're cutting.
This s better for hard or difficult woods than anything else I've tried, because the wing cutter planes the square stock down to near circular gradually. To illustrate this, I just went out and made some 5/16" dowels in Katalox (Mexican Ebony). From the time I walked into the shop, until I walked out with 3 dowels from this very hard wood, was less than fifteen minutes, and that included honing the blade, drilling and setting up the jig, cutting the Katalox, and making the dowels. Of course, the actual making part was just a couple of minutes, and I could have done tens of feet of dowels in a few more minutes. The results are in the pictures.
PXL_20240214_180349917.jpgPXL_20240214_180254782.jpgPXL_20240214_171821109.jpgPXL_20240214_171350942.jpgPXL_20240214_171359745.jpgPXL_20240214_171534556.jpgPXL_20240214_171609621.jpgPXL_20240214_171716725.jpg