Many people say that there's nothing difficult is casting down and across and letting the current fish your fly. Well no, not as such, but in doing that you probably won't catch any more fish than you would just casting a dry upstream and letting it drift down.
Wet fly and streamer fishing is getting more and more popular these years, and I think one reason is the "big streamer movement", primarily from the US, where they really fish huge streamers for trout. There's nothing new about is as such. I fished huge streamers for bull trout when I was in Montana 20 years ago and fly fishers like Kelly Galloup has been promoting and fishing huge flies and streamer for trout for years and years.
But it's rising in popularity, which is think is great, because diversity is good and consistent succes on any water depends on being able to handle as many methods as possible.
When I began fly fishing, I began fishing the salt around Denmark, because that's what we do. In the rivers I fished dries and nymphs, because I was lucky enough to be mentored by a couple of people who were excellent dry fly and nymph fishermen. I rarely fished wets to begin with. But fish don't always rise and in early and late season they might be a bit slow. That's one of the cases where wets and streamers come in.
Rather than just covering water, casting across and swinging, I like to choose flies carefully (weighted, unweighted, small, big, streamer, wet fly etc) to fit the situation. I almost always fish a floating line, because our Danish rivers usually have a lot of weed growth during the season, and a floating line gives good control in steering your fly around, past, even under weeds and in fact also over depth.
The satisfaction in tying on the right fly, casting it to drift down to reach both depth and lie, controlling it's drift with a mend or two along the way, tightening up the line to animate the fly and feeling the strike is every bit as good as getting the same fish on a dry. And it requires at least as many skills.
Just watch some of the YouTube videos of the really good streamer fishers and the array to retrieves and techniques they use - it's quite fascinating.
And when it comes down to it, I think no fly really says "fly" the way a classic wet fly does. So in the PoD, a re-run of a March Brown I tied a while ago.
Have a great weekend!