If you’re getting paid you’re by definition not a volunteer. You may be getting some perks like volunteering at a convention giving you an entry pass for that convention, but as soon as you’re getting some other gains, be it monetary or not, you’re no longer a volunteer.
While videoconferencing does take some resources, the fact of the matter is both zoom and teams are poorly written web apps packaged into “desktop applications” and that’s where most of the utilization is coming from