I’d ask the OP why one of them has to be a “failure”. You can reasonably ask which of the 4 was most or least capable for its era, most or least suited for its planned-for or actual in-use mission, etc. But in fact none of the 4 were a “failure.” Each worked (or still works) just fine in its intended role during its heyday.
The F-14, despite the name, wasn’t really a fighter. It was a long-range interceptor. There is a difference. Interceptors are about speed, and range of aircraft, radar, and missile, at the expense of maneuverability and excess thrust. Which circle the designers tried to square using the infamous swing wings.
The F-14 was utterly bleeding edge tech when designed. Radar, missiles, engines, aerodynamics, you name it. But the state of the art was moving rapidly and in many ways it was behind the times once fielded. While at the very same time being utterly in a class by itself in terms of its ability to do missions nothing else could. On the rare occasions everything onboard was working well.
Between that Day One bleeding edge obsolescence, extreme complexity, and the difficulties of ship-board maintenance, it was destined to have a more difficult service life than the other types. There was an effort to create a radically updated Super F-14, but that died early, as the F/A-18 promised to do both the F-14’s interceptor role (albeit less capably) as well as the A-6 and A-7 roles. USN was facing the need to replace all 3 types more or less simultaneously and having just one type in replacement seemed like a great idea tactically, logistically, and budgetarily. Which has, over the years, proven to be a darn good idea albeit maybe not quite a great idea. So unlucky timing for the F-14.
The F-14 also suffered, like the B-1, from having its enemy evaporate early in its operational life. One the Soviet Union collapsed, the need for the USN to be able to defeat a fleet of incoming bombers 300 miles from the ship largely evaporated. Which was the total raison d’etre of the F-14/AWG-9/AIM-54 combo. Bad timing strikes again.
It’s also important in this discussion to talk about the realities of the service lives of the F-15, F-16, and F/A-18.
The original F-15A model is long since obsolete and in the boneyard. The later F-15C is externally similar but is a vastly different and more capable weapons system. Which has since been upgraded in various ways.
Same story with the F-16A vs F-16C. The A models I flew back in the 1980s are long since wasting away in the boneyard as combat-irrelevant against today’s threats. Even among the much more capable F-16C, USAF has the oldest and least capable F-16Cs in the world’s inventory. The ones Lockheed is selling now to our allies and client states are vastly more capable. There have been, and continue to be upgrade packages for USAF’s airplanes, but they’re struggling with aging airframe issues and also budgetary competition from the long delayed and very expensive F-35A.
As said by others above the F/A-18E is an almost totally different airplane from an F/A-18A. It’s a much greater difference than between F-15 & F-16’s A & C models. It’s a third generation of F/A-18, whereas the -15 & -16 were capped off at 2 generations each.
The latest F/A-18s look similar from a distance, but the E model is about 15% larger than the A/C models. And again vastly more capable for the modern networked nature of aerial warfare.
If we look at the US service withdrawal dates of F-14A, F-15A, F-16A, and F-18A we don’t see such a large discrepancy:
F-14A: 1974-~2000 = ~26 years
F-15A: 1976-2009 = 33 years
F-16A: 1978-2007 = 29 years
F/A-18A: 1984-???? = ?? years
F/A-18C: 1987-2018 =31 years
In each of these cases, by the last few years of the type’s life, they were already relegated to second tier roles. For USAF F-15A / F-16A, that is generally the continental air defense interceptor role, otherwise known as post-9/11 airliner shoot-down duty. With a 737 or 777 as your adversary, you don’t need a bleeding edge fighter, a raggedy old one will do just fine.