1. The biggest thing keeping me tied to Chrome over any other browser is the extension support. Extensions are second class citizens in any other browser. This is partly because other browsers keep overhauling their systems and deprecating old software which discourages extension developers, and mainly because (as an extension developer) why would you code for browser X when you can get more users on browser Y?
2. Anecdotal evidence, but every time an update of Firefox (and most notably Quantum) is released people laud how fast it is. On my 2015 Macbook running Mac OS Firefox has never been faster. Maybe there are things behind the scenes such as caching playing a role, but web pages load slower, scrolling feels sluggish, videos drop frames and freeze or get out of sync. It isn't an enjoyable experience compared to Chrome or Safari.