No, Google Tag Manager supports various 3rd party tools, like Facebook Pixel, Hotjar, etc.

When you use Google Tag Manager (GTM) to add tags on a website, you get more control over: 1) When the tag should fire. 2) When the tag should not fire. 3) Where the tag should fire. 4) Where the tag should not fire and What the tag should do, when it get fired (executed). GTM removes the need for editing the website code over and over again just for adding, removing or editing tags.

GTM is a tag management tool. Whereas Google Analytics is a website/mobile app tracking tool. Through GTM you can: add, edit, enable, disable or remove any tag, with just few button clicks. That is something, which is not possible with Google Analytics. ‘GTM’ is primarily used to route data from one data source to another (like from your website to Google Analytics or from your website to a data warehouse). It is not a data source in itself. Whereas Google Analytics is a data source in itself.