From a statistical perspective it is better to lynch someone over no one. There is always a positive chance that even a random selection will result in a scum lynch. If there is no lynch there is effectively zero chance of killing a scum. By not participating in the lynch you are effectively resigning yourself to the zero chance side of the coin, which is inherently anti-town.
In my opinion even if this isn't persuasive,
By not voting you are giving the mafia greater control over the day's lynch, and during the night they have a distinct advantage.
Town has to have an advantage somewhere, and that is by having enough people to outvote the mafia and also allow for the usual guessing mistakes (margin of error). That's why you should vote.
It's not
super critical d1, the difference between not voting and voting someone with no other votes is negligible here. However, there is something to be said for even those sorts of votes-
Should you vote a mafioso, for example, early enough in the round for it to matter (right now, probably doesn't matter unless you're joining a wagon) then it helps others understand you intended to lynch a mafioso that day.
That's helpful to your team in reading you.
Sure the odds are low, and mafia can vote for other mafia members, but you have increased the odds a mafia gets lynched that day. That sometimes is all you can do.
That's more along the lines of "what is good strategy" and can be discussed after the game in more detail.
It is also a viable idea to deliberately give the mafia more control over the vote by not voting, and keeping the tally votes on any given candidate low to see what they do with it. The problem with that is that it's easy for the mafia to counter that strategy by also not voting, and now there's less data to work with all game. Voting analysis is one of the few villagery things I'm good at, nothing to analyze is particularly bad for me and others who rely on it.