I'd love to see some other thoughts on this question. I use AllTrails and I like the downloadable maps enough that I pay for premium. But I'm still hunting for the app that has good information and is easy to use.
I like the information available in CalTopo, especially good topo lines, temperature information, and up to date info like weather and hazards. But it could use better trail info (in the Midwest, at least). And it has so many layers and info that I find the learning curve more steep than I really want to deal with. If I was a bit more ambitious about learning to fully use it, I might love it. I paid for premium for one year but found that I didn't use it much.
Natural Atlas has really beautiful maps and good topo lines, weather info, and good coverage of official trails (but a bit short in national forests). But on it's unique feature, (info on wildlife, plants, natural features) info on areas in the Midwest is so limited that I can't figure out why it is useful. I'm trying premium right now.
Avenza is very nice when maps are available. If I had an easy way to geotag maps, I would use it a lot.
I tried Gaia years ago but just found that I wasn't using it.