I was weighing this up only a couple of weeks ago.
I’d been riding my old “gravel” bike on both 700×40 and 650×47 wheels. The 700s were definitely “faster” for any tarmac segments and the 650s definitely “more capable” on rougher segments, so much so that I decided 650×47 and front suspension was an unnecessary provision. Add in the extra weight of the lefty, the servicing requirements and the lack of fork cage mounts and it was a fairly easy decision. The fact that the rigid model was around £800 cheaper also gave me a budget for upgrading the wheels.
I’ve kept my old VN Amazon for when I might want the “faster” option again and I also have a Ti B+/29er for longer rougher rides that are really into MTB territory. If I didn’t have those options available to me, my decision might have been different.