The reason it isn't, for me, is that I'm usually answering questions about Why we do something, or How something is supposed to work. I'm usually giving a quick response, with a link to a design, or a code snippet, or a git commit, or a Code Review link, or something online. So I have to provide an online response whether you ask me in person or not.
If I'm in a 1:1, yea I totally agree I'd rather just talk about career growth and that stuff in person. But.... I mean now we are walking down the already-well-discussed path of Manager/IC and how these jobs are just different.
I don't know for sure, but I think this is the experience of many senior developers.
[edit] > I twiddled my thumbs waiting for the required SME to come online
I mean, this isn't an RTO discussion. If your SME is slacking off that is a different problem. Assuming best intentions, you would walk up to that SME's desk and there would already be 5 people waiting with a question because the SME can only talk to 1 person at a time.
I can slack with several different folks, so long as they can just wait a second while I type. The worst people (so sorry, there are some great TAMs) are the ones who page you as soon as they need something because they don't understand you are busy with a different project.