I'm tired of accidentally closing tabs in a group! Pinning them means the "x" is gone, and they stay in the intended group. It also makes the tabs smaller in width, where I have many groups with tabs on several topics and commonly visited items, maki...
I love this idea, tab group is great way to organize tabs, especially if you working and open a bunch then need to work on something else but want to organize groups by work, project and to easily switch between groups.