Sure, you don't need to write everything down - but how many times could someone have simply RTFM if people were more in the habit of documenting institutional knowledge among other things? Even just defaulting to email discussions would help keep track of things much better.
And yeah, when I'm working with other people, I make a point to hang out in a BigBlueButton or other similar instance, with a note with my phone number there, as well as putting in my email signature line my phone and a note that I'm available for videconference.
To head off negative reaction to this, I'm not saying that remote should always be similar hours, I mean remote work positions that otherwise would have been in office before the pandemic, if that makes sense.
I just look at this situation and to me it looks like people are like, ohh noo, remote work isn't as good as in office work, well, yeah, you haven't even tried to make it anything like "in office work but thru a camera," you've almost allowed your domestic employees and contractors to work as if everyone's in different teams in different timezones, with all of the problems that come with that...
Of course, sometimes it makes sense to do check-ins (e.g. for onboarding) or a pairing session, but that can also be scheduled.
I also tend to forget things that were just said in personal interactions or meetings. If it's written down, I can look it up.