What might be the reason behind the declining number of citizens who vote

Explanation:

After increasing for many decades, there has been a trend of decreasing voter turnout in most established democracies since the 1980s. In general, low turnout is attributed to disillusionment, indifference, or a sense of futility (the perception that one's vote won't make any difference).

There might be many reasons but one I think is most relevant is the fact that technology has been advanced. It causes us to think everything is simple and unnecessary in some sort of way ( Sorry it's difficult for me to explain what I mean )

Because everything is as simple as a click on your phone..It makes our responsibilities as a citizen taken for granted

Also they think one vote would not hold much value

Hope it helps :)

answer; ///the above statement is (true); //

you should try adrenaline. it kicks in in situations like this.