Linear is in an interesting category. It's in one way a product tool (e.g. focusing on bugs, feature requests, and sprints/cycles), and another part project management (for managing the tasks around the cycles).
The thing is, Linear is very much built for your engineering and product team to tie in all of this information together. You'd be hard-pressed to use Linear as a replacement for the company's general project management tool.
If you're heavily a product-focused company, and most of your employees are engineers and product people though, you can probably get away with just using Linear as your team's project manager.


