It's always tough when you've been in a leadership role to "sit back and watch"--especially when you know that you would do it differently. That being said, you're in a new school and the culture is obviously different. Rather than take the approach of "they're not doing enough"--why not ask the questions "hey--is there a reason we don't do this, or is there a reason why the principal manages the major fundraisers?" Or--"have you considered this?" You might be surprised to learn that maybe there's a reason behind the "why"---which could stem from anything from the abysmal "that's the way we've always done it" to something more substansive. Or perhaps, there are guidelines and rules that aren't shared, or were shared so long ago and have become part of the fabric that it's taken for granted that "everyone knows" and the veterans forget to share with new members.
A lot of times, I find parents--especially brand new parents--look critically at what I volunteer/volunteered for in the past at my kids' school (I have stepped way back from PTO/HSA, even though I'm a former president, but still maintain a bit of a leadership role on a different level for the school). They have all these "bright ideas" and wonder "why don't we do this or that". While every now and then someone does present a great idea, a lot of times, there's more to the story that they're either not aware or not considering that impacts the decision making process---often much bigger than even our school administrators (for instance--the diocesan rules supercede all else in our school). Often times, too, the idea has been discussed and dismissed well before the person brings it up because it's been thought through carefully and the benefits vs. negatives have already been weighed. Once that's explained to someone, it often clicks---though I do leave open the thought "well, certainly, if you can see a way to work this out, given this information, please feel free to re-present this idea with a plan."
By the way--I say this as a veteran--but I was also a new parent at one point, too, looking in and wondering "why don't we...". It's taken my several years to understand the dynamics that come into play with our school's decision making, and is in part the reason why I've honed on to one area in which I can make a difference and focus my energies there now.
And I'm sure next year, when my daughter goes to high school at a different school, I'll be asking those questions all over again, too.