I'm gonna die on this hill but I'd like to add that Opera had tab groups natively without extensions since 2010 [1]. Damn I feel old now.
Also, UX of tab groups in old-Opera was way nicer than current-Chrome since you could just drag and drop tabs on top of another and it would automatically create groups.
[1] https://www.computerworld.com/article/2512081/opera-11-ships...