do you think PR has become more of a mainstream issue in recent years? Because I've heard articles in the guardian as well as a people around me mentioning it

I don't think it has. The previous AV referendum had the same level of fringe interest too around a similar stage to this. The Lib Dems were the ones to push it through in coalition and against heavy opposition from the Tories (who watered it down) and veiled opposition from Labour (who like the EU question didn't do jack shit and sat on the fence) so it absolutely tanked. It didn't help that thousands of student voters saw this as an opportunity to "fuck tuition fees" and vote against anything supported by the Lib Dems. Since then I don't think a lot has changed in terms of coverage or main stream support. And, you know, that other referendum happened....

For example: how often do you hear about this on the daily news cycle versus hearing about anything Brexit related? Instead of XYZ news story can be partly blamed on Brexit do you ever hear ABC news story might have been different and more equitable under PR? Literally every single political and economic story needs to be about this for a sustained amount of time before this becomes mainstream again. Or Labour needs to swallow their pride and force the issue for the sake of the country.