Review is indeed the main bottleneck now for open source, and we need to solve it. Introducing more friction is hardly helping.
A company is usually already a high-trust environment, where people use real names and have real reputations. So creating an issue cannot serve the purpose of increasing trust.
I can see why that doesn't sound great particularly on a team where everyone knows each other and is working together but it totally makes sense for me if I were maintaining a project that was large enough to get a lot of low-effort PRs coming into it.
To my understanding Code Review is first and foremost a trust-building exercise, seeking to establish common understanding behind the piece of code which is to be delivered. That it also may lead to improvements or "catch some bugs" is a distant tertiary side-effect, not the primary goal. At least this is the vantage point I reviewed any code from in the last two decades, and found that team morale and overall quality of teamwork - and delivered software, and customer satisfaction, as a result - responds very well to such interpretation. Regardless of the side you are on and competency level of your vis-a-vis. I would put "elevating competency level of both partners" as a secondary goal of Code Review, and very closely connected to the primary.
With current crop of LLMs there simply nothing on their side to which words "trust" and "understanding" can be meaningfully applied. Hence the "review" takes drastically different shape and implies very different goals. As both the primary and secondary goals described above cannot apply too. The only remaining goal of "improving and bug-catching", in absence of trust, understanding and learning, now requires much more work, which is also much more exhausting.
I find it actually extremely useful practice. We engineers tend to center our thoughts around "code" and with such code-centric mindset to accumulate knowledge as "code-adjacent" - in repo's commits, PRs, markdown files of all sorts. But in reality most if not all projects extends past the code, and it makes much more sense to have a "project-centered" mindset. As such, an external "issue" captures much more context and provides more useful insight about project impact than PR description alone. Love or hate JIRA, beyond microscopic solo-projects it makes full sense to use broader-scope external tools for project management.
As a nice cosmetic effect it also removes (some) bickering about whether to put "type" or "scope" first in the commit message :). Simply provide a reference to the ticket! (No, really, I hate JIRA, honestly!)
I'm a world champion bikeshedder, and I both hated this policy and insisted we keep it.