https://geology.com/articles/helium/uses-of-helium.gif
It is lumped into the "other" category on this chart.
One of the problems is that our helium supply comes as a byproduct of the oil and gas industry so as we switch to renewable energy sources the yearly supply will diminish even as demand increases.
So party balloons may become unaffordable but that won't affect the total demand very much. Or maybe we'll have far more exciting party balloons filled with hydrogen gas instead.
Far more exciting, of course, because the balloons will explode. My kind of party!
Unlikely. It is not a byproduct of the oil industry. It is very specifically a byproduct of the gas industry. NG is the least carbon intensive fossil fuel so it's likely to lag. Further, you can separate and reinject.
Party balloons are a 100% loss though, so even if they're only a lesser fraction of that 13% "Other" category (7%? 4%?) every bit that goes there ends up vented so I could see that adding up over time vs others.
Ideally proper pricing would help take care of this but that's pretty hard for something like helium.