I used
Oruxmaps a long time ago just for a comparison to my Edge 500 and to use when just walking. It did a lot back then circa 2012, but I haven't used it since. It was completely independent of the need to have a cloud presence to view all your metrics. Though Strava, RWGPS, GarminConnect and other have gotten better at showing you stuff on your phone about your ride. But not so much while you are actually doing your ride as Oruxmaps did.
Oruxmaps at the time did way more than just cycling and the UI was sometimes complicated to navigate. But that was years ago. Don't know about current which apparently is still going strong.
I still prefer not to use my phone. One reason is that I"ve never had a phone that I could see well in sunlight. And the other reason is that I'd rather have my phone somewhat safely tucked away in my pocket so if I crash and get separated from my bike, I won't have to hope that I can crawl back to the bike and find the phone still on the bike.