I try not to waste their time and develop my questions as much as possible on my own, but I'm not going to risk several hours of wasted work going down the wrong path when a 5 minute discussion with a SME would confirm something.
And it is an RTO discussion, because in the office they're available to some degree. WFH that availability drops off a cliff, and these are questions about the inner-workings of proprietary software, if the answers were on Google there would be legal action.
It seems like what you really want is for others to treat your emergencies as theirs. They're not, they're yours. If you can't wait 15 minutes for a ping back without being completely stuck, you aren't planning your work correctly. That's nobody else's fault.
A good analogue is the culture of "the smoke break"(see the Friend's episode The One Where Rachel Smokes for a funny example). It's easy to say "the best decisions are made during smoke breaks therefore smoking is necessary for efficient businesses." Clearly that's absurd. It's not the smoking that makes good decisions, nor does the ability to tap people on the shoulder make for good documentation. Depending upon an accidental formation of office culture is never going to go well in the long run.
Viewed a different way, it allows a team to spend less time documenting and more time on other things. Increased documentation could be seen as one of the costs of working remotely.
All this to say, the trade-off you're proposing doesn't exist. You're arguing for paying twice instead of paying once - twice in the sense that you lose productivity now via random interrupts, and in the future when your siloed knowledge leaves you high and dry. Hope the "other things" you got done instead of documenting were worth it in that scenario.
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.