Terror Tactics and Techniques for our Times

Stop and think about terrorist tactics over the last decade for a minute, if you would. Al-Qaeda and similar groups tactics, at any rate, if youre confused about what constitutes terrorism and what doesnt.
Weve seen traditional explosive-vest suicide bombings, VBIEDs, regular IEDs, sniping, the use of explosively-formed projectiles, the use of jets as weapons, the use of rockets and mortars and other indirect-fire weapons, and a couple of obscure oddities like camels rigged with explosives. (No, really.)
What kind of surprises me, though, is that when you start looking at specifics, a lot of the most spectacularly successful techniques were only used for a brief period of time.
Ramzi Yousef blew up one plane, and put a hole in another, and that was pretty much it for trying to blow up airplanes in flight (at least until we invaded Iraq and everyone got their hand on MANPADS, and even thats been pretty unsuccessful). Some folks in a boat put a gaping hole in the side of the USS Cole& and nobody seems to have tried that again since. Four jets were hijacked and turned into weapons in September 2001, and& that was it. For a while, EFPs were in the news every day, putting holes in anything and everything they were aimed at. Then& they seemed to just disappear, as far as I can tell. In the early days of the Iraqi occupation, snipers like the possibly mythical Juba killed and wounded dozens and dozens of allied soldiers. There are still snipers, it seems, but nothing like what there used to be.
Why is that?
Some of it might be attributable to shifts in tactics by western forces and governments, but not all of it. Whither the EFP? Nobody ever conclusively answered whether they really were coming from Iran or not, but that several Iraqis were arrested in connection with them, and now you dont get em anymore, suggests, to me, that they were an indigenous product with no outside backing.
But that doesnt explain why additional USS Cole-style bombings have never happened since, or anywhere else. (Even the Tamil Tigers, as crazy a bunch of extremists as youll ever come across, and who had pitched battles with the Sri Lankan navy - and usually won - never resorted to blowing up boats full of explosives in the process.) Oh, navies made changes in tactics following the attack, but as far as Im aware, nobodys even tried since.
There are still terrorists willing to martyr themselves for the cause, but it seems like everyones pursuing low-budget, minimal-planning instant gratification. Its weird, really.
Im not complaining about the lack of successful, high-profile terrorist attacks in recent years, mind you. I just find it weird that the IED and the truck-bomb seem to be the enduring terrorist techniques of our time, is all. Oh, theyre effective, Ill grant you that, but so were a number of other things that, as acts of terror, were subjectively much more effective. (Sure, a VBIED could be anywhere, on any road, anywhere in the world, at any time& but how much do you really worry about that? Probably rather less than you do about the airliner youre on being hijacked and turned into a missile, or the ship youre on being captured by pirates or being blown up by terrorists. As tools for striking fear and terror into the hearts of infidels the world over, the IED and VBIED are, when all is said and done, kind of meh by now, you know what Im saying?)
For that matter, its been a couple years since any terrorists surprised the rest of the world with a new or novel tactic or technique. Why might that be?
Discuss amongst yourselves.