Yes, but the reason they're used is because it's infeasible or too expensive to build an aircraft carrier long enough to have jets reliably take off from them without this extra boost. Even so, those catapults are fairly short: notice they're only a fraction of the length of the carrier.
They're not used in regular airports because they're not absolutely necessary, the way they are on aircraft carriers. It's more expense, and planes can do without them. However, there's a cost to this: the planes need bigger engines and more fuel to take off reliably. And bigger engines are less efficient overall (as in cruising). So there would be a significant fuel savings if you could count on having catapults on the ground to help get the plane to takeoff speed: you could downsize the engines, and carry less fuel, saving a lot of money overall per flight (not to mention all the carbon pollution).
Finally, the extra g-forces shouldn't be a big deal. There's high g-forces in a carrier launch because the catapults are very short. And until recently, they were steam powered. This needn't be the case with commercial aviation: they can use modern electromagnetic launchers, and they can make the catapults very long (as long as much of the runway), to have lower peak acceleration. Basically, the planes and passengers would not need to experience higher g-forces than they already do; they'd just be getting them from the catapult instead of solely from the engines.
But having also launched from a carrier myself, I wouldnt want that g force everytime I fly commercially.
If I was a carrier pilot, I doubt I'd ever get used to that!
It's actually an interesting supposition, because whether it's gasoline or electric, it should be cheaper and more reliable to run a ground operation than to pack fuel that is expelled before anything meaningful has happened.
https://en.m.wikipedia.org/wiki/Space_fountain
https://en.m.wikipedia.org/wiki/Cloud_Nine_(tensegrity_spher...
That seems quite dangerous - to both the aircraft and everyone onboard, as well as to anyone on the ground in the path of this cable.
Simply put, that's just not how aviation works.
Mechanical failures aren't uncommon in aviation, but for an aircraft to not be able to divert and return to the ground, a lot has to go wrong all at once. It's infinitesimally rare for all systems to fail at once on an airliner. There simply isn't a problem of airliners dropping out of the sky, ever. They're incredibly robust machines.
However, with your idea, we'd be relying on a single system to prevent catastrophic failure. That's a massive step backwards for aviation.
That doesn't even begin covering the problems with delivering enough electricity over this cable to power an airliner at takeoff... That cable would need to be a very thick gauge of wire and very heavy - causing all sorts of it's own problems.