In terms of campaigning, the “no” campaign always has the advantage if they can make their case well, because if you vote no, you continue with something known. At the time of the campaign, “yes” is an imaginary thing. Yes is this virtual world, this thing that has to be described to you. No one has lived it before. So the modus operandi for a no campaign is to find a worst-case scenario and run with it. It's very easy to do that if you know what scares voters.
The yes campaign has to find a simple, urgent, and direct message to try to relate it to people's lives. It can be done, but it's harder. I would say that, if two sides are given equal amounts of money, the no side still has the advantage because it's just built in. It is advocating for something that people have lived through, while the yes side is advocating for something that, at least at the moment, people can only imagine.