Wheel size, if you avoid the extremes and separate out the other factors, makes approximately zero difference.
That said, for a smaller rider, 29" wheels are extreme. I just don't see the point of such large wheels.
Now as for the other factors I mention, the big ones are "what tires are available" and "what rims are available.". These days the selection in both 650b and 700c is excellent, so there is really no big reason for a reasonably tall person to prefer one size over the other. Five years ago I had misgivings about riding 650b wheels too far from civilization, but the size is so common now I wouldn't worry about it.
I've been riding a Rawland xSogn lately. 650b x 48 tires, drop bar, steel frame, disc brakes, 1x11 drive. In the last couple months I've ridden it to the station every day, and a couple 125 mile recreational rides. Almost all my riding is on paved surfaces.
I don't know if this is factually true, wheel sizes drive the size of tires you can run which make a huge difference. Tire width and diameter make a huge difference the the determinant of your tire width and diameter is driven by your wheel width and diameter. Sounds like your riding experience is pretty narrow so maybe doesn't make that big of a difference to you....