Of course, but it depends on the structure. If you have more decentralized organization (like a more open project that has external contributors, or a student organization), you still want encryption for board members, but more open access than a silo.

I am totally against centralized third party entities such as Telegram or Discord having access to conversation. It is not binary and I don't want to feed surveillance. For example you can setup matrix in such a way that new entrants to the room does not have keys to older messages. Yes, people can always screenshot and leak. But that is way different than a huge entity surveilling and possibly correlating all activity on the service.

For me, signal is good enough for example, I've run several companies and projects just on signal groups. But grouping element/discord/mattermost/slack style is also useful.