Is there any point?

Harry Monk:

AndieHyde:
"If voting made a difference, they wouldn’t let us do it. "
Samuel Langhorne Clemens (November 30, 1835 – April 21, 1910)

snopes.com/fact-check/mark- … ing-quote/

It all well and good trying to debunk whose quote it may or have not been, but more to the point is the statement correct?
In reality what difference does the ordinary persons vote seem to make in most well established “democracies” ?
As it costs a lot of money to run an election campaign and a great deal of help to rise to the top of the greasy pole of politics, those that we vote to represent us are more beholden to others than the electorate, so those that really got them into power will be the ones who call the shots.
And I can pretty much say regardless of who I vote for, I’ll get a conservative MP where I am, and throughout of much of the UK the same party will get represent the constituency as have done for decade, so the government is really decided by a few floating voters in a relatively few constituencies.