Only for azure devops, there are +6k problems listed on developer community website with 500 still not closed for the last 6 months. [1]
The complete integration in the ecosystem is what's flawless.
Any company with a better product has to fight that integration and they almost always lose (Sybase, Borland, WordPerfect, Lotus, Netscape...)
1 : https://developercommunity.visualstudio.com/AzureDevOps?ftyp...