Thanks. Not something I’d want to do (I like my work and personal tabs in totally separate windows) but obviously that’s just personal preference.
It’s pretty useful at work because I can separate the about riddled with sales trackers from asking for quotes from my “how do I do X” profile. It can change the results a fair bit. On one I’ll get tons of Enterprise professional services, the other recommends a lot of FOSS results.
Plus you can make certain sites always automatically open in their designated container, even if you followed a link. You can keep sites know for spying away from your logged in identity. You can have your banking and other important sites in another container for extra defense in depth.