Here's some arguments in favor of public comments and conversations:
- Public communication about pull requests encourages knowledge sharing, not just between reviewer and reviewed, but anyone reading. It stores this knowledge sharing long term, so that any future reader can read up on the context and back-and-forth done to get to the chosen solution.
- Meetings are transient. Unless someone takes minutes or a recording/transcription is made and shared, it means the communication in that meeting will be duplicated when it has to be shared elsewhere.
- While I do think the author and reviewer share responsibility for the code in question, merging should be done by the author so that they know when it was merged and can jump in if something goes wrong. That said, in an ideal world it shouldn't matter who hits the merge button, and in fact, something should be automatically merged if it's approved and the pipelines are green, but that's uncommon.
I'd take notes if you ever notice waste from e.g. private / unrecorded meetings, or if someone has to repeat things said in a meeting; take it to a manager and hint that there is a lot of waste.
But ultimately, don't make it a hill to die on. I dislike people going "hey can we do a call" as well - I'm usually busy / elsewhere / focused on something, and there not even being a hint on what it's about is aggravating. The person asking it clearly believes their time and attention is more important (as in "I need feedback on this now"). Sending people that link (after ignoring them for X amount of time after sending a "hey") is passive-aggressive, but educational. Ultimately though, it should be higher-ups that encourage a culture and the etiquette of asynchronous communication.