It's hard to say without knowing what things are like at the company/team you work for, but I can say the things you're describing sound unusual to me.
Most significantly, it's strange for the person writing the design doc not to be the person implementing the code. This is asking for trouble because there's a principal-agent problem[0], and also there's bound to be signal lost in the handoff between designer and implementer. It's not so unusual for the design doc author to work with a team on implementation, but they'd still be actively involved in implementation, which sounds different from what you're describing.
I've also never heard of this separation between a conceptual design doc and a logical design doc. I've been on teams where the product manager writes a UX-focused spec, and then the dev writes a technical-focused spec, but I've never heard of a conceptual vs. logical spec.
Does the org have a strong engineering culture in other ways? Like automated tests, automated deploys, automated monitoring/alerting, useful code reviews? Because the easiest answer is that you're in an org with poor software engineering practices, or at least weak documentation culture, and the design review process you're experiencing is there for historical or political reasons rather than engineering reasons.
[0] https://en.wikipedia.org/wiki/Principal%E2%80%93agent_proble...
Well, there's a fascinating insight, most orgs I've ever worked for have had the documentation produced by someone else and them implemented by the developer.
For instance the enterprise architect/solutions architect ( or whatever job title is fashionable at the time ) would write the document and then send it over to the development team and obviously that wouldn't work.
I actually adopted the conceptual/logical design from two ex Hewlett Packard engineers/architects who introduced the idea to me, probably some twenty years ago now!
Yep we're strong in many other ways, but finding the transition to AI challenging :)
Reviews have somewhat turned into, I send you the output from my AI agent of choice, and you tell your AI agent of choice to fix it :)
Thanks again for the time taken to reply :) It is appreciated.