Besides lack of depth, many clothing companies make their pockets out of the cheapest, flimsiest material available. You can wear them out with coins, much less keys or firearms.

I've found the Carhartt washed duck pants to work well and have fairly stout pockets. I'll have to look into the DTC pants.

Once upon a time, I had a couple pairs of uniform pants with pockets that were both deep and heavily reinforced.