I agree the need to adjust for water depth and change up your presentation, especially for very fishy spots. Let me tell you true stories years ago.
Story1: I was fishing between Train Bridge and Bergman one morning w/o success. Then in late morning I saw a fish roll at a deeper fishy spot in lower river that I casted before. Since it was a small spot, I decide to test out different water level and tried everything in my arsenal, roe, shrimp, pink worm, spinners, etc. Only after about 20 minutes of trying and at a certain depth adjustment that I finally had a take down. A fierce battle followed with a large steelie. Wow what a reward, a 16 lbs hatchery buck. It made me wonder how often we missed fish by rushing too fast. I think if you fish a pocket water in the highly oxygenated rapids, you probably will get it to bite within a few cast, perhaps even the first cast. But in lower river where fish have seen many presentations, it may take some repeated effort to get one to bite.
Story2: about 5 years into steelheading, I thought I was a pro, only to learn a bitter & embarrassed lesson. I was fishing with a newbie in a good run which we combed for an hour or more with no result. We used pinky stuffs, roe, worm. Nothing. So I told the newbie there wasn't any fish in the run. How wrong. An old timer guy walked in as we were about to leave. He proceeded to hook 1, 2, 3, 4, 5, all of 5 wild steelies right in front of us, with our jaws dropped. We looked closely after a few fish what he used. It was just wool, but with 2-colour combination most guys won't use. That day really opened my eyes and humbled me. It taught me to be open minded and to be willing to try out different things than my mere roe & worm. LOL.
Story3: an old timer friend of mine surely knows something I don't. Years ago, we were heading up river. He stopped at a location near Thurston Meadow camp site, a run called 'the butterfly' (now gone). There were a few cars already there and a few fisherman combing the tiny run. I said let's try somewhere else but he wanted to try it. He looked at others on what they used and proceeded to take out a spinner of a rare form and colour which he told me later only available in the States. I can never forget the sight of him hooking up into 1, 2, 3, 4, four steelies in the small run combed by those guys plus me. After fish # 2, guys were all switching on spinners but not with his colour and shape. He proceeded to hook 2 more while all of us were skunked. Once again it reminds me how steelhead can be so picky on some days. Since then I have acquired and used that spinner and on some days digging out fish among many rods in busy run that just amazes me to no end. Try change up if one thing doesn't work. Don't be lazy.