As Google rolled out its Meet video calling service to users, the company added it to Gmail's sidebar. For users who don't like that it takes up space there, you have the option to take it out. Unfortunately, this option is only available to G Suite customers. If you use G Suite and want to take it out, you can head to Gmail's web preferences (the gear icon in the top right corner) and locate the Chat and Meet menu. There will now be a Meet section there that you can toggle. If you want to hide Hangouts as well, you can do so here, too, under the Chat option.
If you're a G Suite admin who'd like to do this for an entire domain, there is a different setting for you to do. But for individual users, it's as simple as heading into your settings to enact the change.
Source: 9to5Google