My Capture One Pro catalogue will reference this storage, and I've found that the speed difference between SSD and spinny disc is considerable, especially considering each of the recent images (in the last year) are 85MB uncompressed RAWs. In practice I find it difficult to separate current photos from "archive" ones, as sometimes suddenly a series of photos from several years ago becomes a live project, such as right now, when I have to produce a selection of re-optimised images of older photos for use on display and marketing material for the charitable organisation that I'm a trustee of. As its "just growed" rather than been created with a formal strategy right from the start, I think separating and recataloguing it is a very major project that would take me half of my retirement, and I just don't have time right now.
I do appreciate that my use case may not be typical! As well as general photography for my own enjoyment I also do event photography for Hampshire Regency Dancers and the Napoleonic Association, and hold the photo archive for the Friends of Sierra Leone National Railway Museum, and also hold the originals for part of the British Library endangered archives project (the Sierra Leone railway related stuff) as sadly they can't afford to store it at its full quality, so the publicly available online resource is at reduced quality, which is probably not a major issue for most people, but we often need to study old photographs in ridiculous detail, looking for clues to historical issues.
Yes, it does get backed up very regularly, and there are offsite copies of the critical stuff!