I have 128gb and a Threadripper (3970X which is 32 real cores). I have been disappointed in lightroom's performance on it, not because it is particularly slow, but because it did not get a lot faster when i changed from a 4/8 core machine and much less memory. Classic has gotten better over the years in parallelism, but it is not good. I think the architecture and Lua combine to make it difficult for LR to actually use all the resources modern systems can through at it.
Relative to paging: There are a lot of misleading statistics in windows, not that they are wrong, but they are misleading. The number of interest to see if you are memory constrained for a (normal) program is "Hard Faults". Go to task manager, performance, then Open Resource Monitor (bottom), and on that window go to Memory. It shows all the processes and look at the column for "Hard Faults".
Hard Faults are normal when a program is starting -- most programs use that mechanism to read the program into memory from disk. So you need to get Lightroom up and running for a while, and be doing whatever your normal work is, so that it is all in memory and ready. Then as you work, e.g. build a bunch of previews or exports or whatever, watch to see if hard faults has significant numbers there (say more than a dozen or so over time).
You have to look at it in the context of how much free memory is available (it shows right under that). If free gets small, you have memory constraints. If free is large and you still have significant hard faults, it is Adobe's fault, they are not making use of available memory efficiently.
Below (first screen shot) is mine running a 1:1 preview build of a folder not recently touched. It's consuminga nice 46GB, and faulting just slightly (it appears to be the cause of "MsMpEng" faulting as well which is Microsoft's anti-malware engine which kicked in probably from all the new files being accessed).
But here's an example (2nd screen shot) of Adobe's parallelism working well. I am running a preview build of 3900 images. Notice the CPU graph is darn close to 100% all the time. That's with 64 cores, so it parceled out those images to a LOT of threads.
But if you do some jobs where things seem to go really slowly, and watch the CPU and disk and other settings you will see times when Lightroom is running very slowly, and nothing is busy -- CPU's will be near idle, disks will be near idle, etc. The cause there is usually that it is single streamed, only one (of your MANY) CPU cores is actually being used, which reflects on the CPU busy time as almost negligable in use. But since it is single threaded, that is all that it can do. Those are when Lightroom really pokes along, and it's not a system thing, it is an Adobe architecture thing when it happens.
Lightroom is OLD code, OLD platform. It dates from when having two cores was impressive, not 64. Adobe has done a lot to improve the spaghetti mess it must be under the covers, but there is a LOT to be done.