There is a pretty extensive discussion about what’s going on here: Activity logs - Sorry!
The short form as I understand it is that there were numerous requests to be able to have greater ability to approve and/or control events being added to the various logs, particularly at the troop level, since it was not uncommon to see non-scouting activities (or activities which didn’t qualify) being logged, which made it difficult for leaders to rely on the contents of the logs for review/approval of advancement requirements, OA eligibility, etc. Creating the ability to generate that review/approval was not feasible as the existing Scoutbook logs were architected, again as I understand it. When they were reimplemented in IA2 (scoutbook.scouting.org), they were subjected to the pre-existing limits on database access/entry for IA2 (Unit Key 3, Key 3 Delegates, and Unit Advancement Chair). IA2 has always relied on the positions as designated at my.scouting.org. The unintended (I think) consequence of moving the logs was that this immediately limited access to enter, review, and approve the log contents.
I’ve made no secret of the fact that I think the logs changes were “shipped” before they were ready for prime time. There are still many things I find nearly unusable about them (the UI/UX prime among them), but as far as I can tell access was not limited as an indictment of leaders, parents or scouts. It was the result of releasing the new log system before it was configured to permit reasonable (IMHO) access controls, rather than the overly-restrictive ones that have always plagued IA2.