Probably not, but all these superstitious beliefs often revolve around a desire for justice when it's lacking in this life, in this world -- whether it's karma or punishment by eternal hell-fire. It might comfort people thinking about it.
People who believe in that kind of instant karma in the same lifetime usually only pay attention only to "hits" while ignoring all the "misses" where people get away scot-free, same kind of thing with those who pay attention to prayers being answered but ignore all the times they aren't. It's a fundamental part of human superstition to pay attention to incidents that align with their beliefs while ignoring those that don't.
In all objective reality, no. Not necessarily. But usually it tends to just end up as an true thing about reality anyway. Safer to live life assuming that Karma does exist, even if you objectively know there's no such thing.
Karma is just putting a supernatural spin on common sense. If you repeatedly do something wrong (ie cheat on someone) eventually someone's going to do something in return that either hurts you just as much or even more