All the whizzy bells and whistles are nice, but if you want a modernized/updated at the core in Windows 7, that apps utilize when embedding browser functionality, some add on third party browser fails.
These are not some "whizzy bells and whistles" but extensions that provide important functionality for those who know and use them. And I have daily run two installations and profiles of Firefox ESR 52.9 with over 300 tabs or more open in frequent heavy duty use, and there have been no problems with apps not working, with only a rare web site not rendering. Which is no problem since a simply right click Open with and the other browser I choose does it. And with no viruses/malware in years, thank God. But the fact the minimalist Chrome, pretty much a sedan versus a utility truck, is by far the #1 browser indicates that most people just go with the flow or have no use for much more than some "whizzy bells and whistles" versus very useful enhancements.