The problem is mainly that the user interface is in my opinion horrible. Especially for new users (I've helped a few newbies), it's hard to see the tabs and to be aware that the browser created a new one.
From my limited experience using it (while teaching an intern how to do web dev), the Dev Tools are horrible and byzantine for some use cases - seems like while Chrome super charged their Dev Tools after the blink fork, Safari's got stuck in the past.
I find Firefox's Dev Tools far better, except the JS debugging tab, which is behind Chrome's on almost all counts.
I find Firefox's Dev Tools far better, except the JS debugging tab, which is behind Chrome's on almost all counts.