The primary reason there is so much variation with the Lee-Enfield family of rifles is the same reason there's so much variation with the AK-47 family of rifles...
They were made by a significant number of manufacturers in a variety of nations.
From the British Government at Matlby, Enfield, and Fazakerly to Birmingham Small Arms (a private company) to Savage Arms in the United States to commonwealth arsenals in Canada, Australia, South Africa, and India.
The M1917 and the M1903 rifles were made by three and two manufacturer's, respectively, and two of the three makers of M1917s were, IIRC, simply different plants owned and operated by Remington Arms.
"this is probably why other rifles like the K98 or 1903 are held in much higher esteem than the venerable enfield."
I would say that that is probably the farthest thing from the truth...
How many different flavors of Mauser are there? Quite a few more than the Enfield, truth be told, and yet that doesn't seem to drag the gun down.
I'd say that, at least in the United States, the primacy of the 1903 and, by extension the Masuer, is simply one of somewhat brainless homerism fueled by a combination of patriotism and a distinct lack of knowledge and experience...
"Iffin it whuz made in the Unittid Stits itzda best evurh! Evvrithin' else sucks pond whuttur!
The Mouser? Ittin what was the granpappy offinda 1903, so itz OK, to, boy howdy!"
Ok, that was a little over the top, but damn it's close to some of the homerism that you can encounter at some of the ranges I've been at over the years.
Shooting foreign rifles and driving a Japanese car?
I make certain I have my 1911 with me. When they see that they get all misty eyed and start talking about what a true chosen of God was John Moses, and how every other firearm ever designed stole from his ideas, even ones that were designed before he was born... Gives me time to make a hasty retreat.