I was a poll worker and observer during W's election. We weren't paid, we were volunteers -- people from WA were in the area and we reported anything suspicious and they came to the precinct as quickly as they could. Also we counted voters going in which in turn had to at least come close with how many ballots were being tallied or the foul was obvious.
I think it helped. It certainly didn't hurt.
An absolutely critical component to fraud-based challenges is having eyewitnesses on scene who can swear out affidavits based on true personal knowledge. Not assumptions made from a distance, or what is seen on TV.
I've spent a few hours one on one with someone who was in the room with Trump and his advisors regarding election integrity and the run up to January 6. This person is a very experienced trial lawyer who was high-up in DOJ and has testified before Congress.
He said there was a massive gulf in understanding between the few people with real trial experience, and the non-litigator lawyers like Eastman advising the President. The non-litigators in the room were convinced they had valid evidence of fraud, while the experienced trial attorneys said the affidavits were conclusory, lacked personal knowledge, and would have been - and were - torn apart by courts.
So the point is that the more people you have on-scene in more locations, the better chance you'll have of both deterring fraud, and doing something about it when it happens. Still not 100% protection, but it definitely improves the chances.