I am averse to paying a monthly fee for use of Lightroom
I confess I don't quite get that. For $10 per month or thereabouts you can get both LR Classic and Photoshop (a combined value in excess of $700), always up-to-date. Nothing is locked in. You can still access you images (but not edit them further) even after the subscription lapsing. It's remarkable value.
I have no doubt that CaptureOne, DxO PhotoLab and OnOnePhoto Raw are as good at processing images as LR is, and in the case of CaptureOne and Photolab, probably better, but none are as good at managing the images. Mylio is close on the management side but no match on the processing side. However it is designed to be used with other processors very easily, so, for instance, I use a combination of Mylio for management and Photolab for processing, and it's quite seamless.
All of these apps have free trial periods. Make a quick collection of say 500 images, download the apps in turn and experiment. See what results you get, and what is to your liking and budget.