Don't worry, he's speaking for the majority of long term firefox users. You're the exception. I started using Firefox when it was Gecko/Phoenix in 2002, then Firebird, then Firefox. I started using it because it was so customizable. I stopped using it at version 37 in 2015 because that was when Mozilla destroyed the browser by removing user freedoms to install their own add-ons without Mozilla's approval. And no, using Nightly (alpha renamed aurora renamed nightly) is not an option because it is extremely crashy on non-standard OS/Distros.
Since 2015 Firefox has become rapidly less capable and rapidly more 'secure' for non-technical users. It's just not what I or the original userbase want. But like with all things Mozilla (including the original employees and CEO) we've been replaced. There's plenty of users who just want Chrome that's not labeled Chrome and Firefox modern gives it to them.