How would racing on a circuit make it impossible for someone to deliberately ignore a blockade or drive out of their driveway into the peloton, which were the two issues at play in the big incidents here? Only if you completely barricade a circuit with barriers does it become impossible, and that's both way more expensive and labour-intensive for a race organiser and also causes way more headaches for residents/local authorities because the roads will be blocked for a significant time before and after the race too. Aside from that, there are other issues at play - in the Dutch national circuit, where it's either do a circuit race or not do a race at all this year, many organisers are not able/willing to do so for a variety of reasons meaning the calendar is heavily reduced. So that suggests that, if you translated that to the UCI level, forcing smaller races to run on circuits will kill off many of said races.
In addition, we've seen major security issues on circuits too - the 2019 Ster ZLM Tour comes to mind, or if we include time trial routes (which are basically the same story where security is concerned) the utter mess that was the 2022 Bloeizone Fryslân Tour. I'm sure there's more, just going off the top of my head here.
If the organisers had outright failed to apply the relevant measures at side roads it would be a different story, but by all accounts that wasn't the case and they were mostly just unlucky. We should be thankful that part of the peloton recognised this (Benjamin Thomas, the rider representative who voted to continue, even said something similar at the vote) in the heat of the moment. And that's no mean feat - it's completely understandable that tempers were running high at that point in time. But it might very well make the difference between the race running and not running next year.