Teams is needed if there are going to be lots of participants in the online videoconference (which was the only metric where Zoom trumped all rivals, especially during the pandemic lockdowns (when Zoom was the only videoconf app that worked for online classes or office meetings that could support lots (100+) participants), but its rivals quickly learnt to fix their issues and scale up, so they are good now.)

Otherwise Google Meet or WhatsApp are more than sufficient. They can support up to 20 participants with ease, based on my experience.

For bigger conferences, Microsoft Teams is the way to go. All it needs is the host to have an Office 365 subscription, then others can join on the browser or app with no restrictions.

Microsoft Teams offers a free version that allows users to chat, meet, and collaborate with others, although it has some limitations compared to the paid versions. The free version includes features like group calls for up to 60 minutes and 100 participants, along with 5 GB of cloud storage per user. Teams will warn in advance before the 60mins is up, so the host can simply end the Teams meeting session and start it again to get another 60mins of meeting time where everyone else can join in again.

No need for Zoom and its security issues.