Plenty of stuff gets built with just email and IRC. My team never turns on their camera because it's just an extra hassle and we get plenty done. Most of our collaboration happens over IM and PRs along with a short scrum at the beginning of the day. We used cameras for a few months and it added nothing to the meetings.
A lot of people mention whiteboards. I only do white boarding a few times a year but IME the best is to get a cheap (under $50) drawing tablet and use a whiteboard app (webex even has one built in, I use whiteboard.com for my side projects and tutoring.) One of my coworkers tried pointing a camera at a physical whiteboard and it was super hard to see much of anything.
Being able to see the faces and body-language of your colleagues by being on-camera during the meetings solves most of that higher-bandwidth comms that in-person brings, and using either a simple drawing app or even something like MS Teams' Whiteboard app lets you get that whiteboard like experience.
I suspect if companies just standardized on some tablet/drawing pad hardware and software--and gave it to employees--a lot of the complaints would go away. I'm not sure it's mostly a technology problem at this point.
Our larger scoping/planning/brainstorming meetings are spread out enough that an hour-long planning call isn't that much of a burden, rarely more than once a sprint if even that frequent. We instead try to pre-plan or hash out things in threads and emails ahead of time, then use those as notes/outlines for a condensed call.
Far more common for us is an impromptu 15-20min discussion after standup to help unblock someone on the team, or a huddle when someone is stuck in the middle of the day. That fluidity feels more like the kind of casual interaction you'd get asking for help in-office.