Turning Firefox into a Chrome copycat* with built-in blocklists and Tor Browser Bundle features certainly didn't make it gain more users. Mozilla should've left Brave occupy that space. Brave, Pale Moon and Vivaldi deserve praise.
The thing costing Firefox users is the billion-dollar advertising push and heavy promotion on Google properties. That won’t be changed by trying to satisfy a small number of critics who are not exactly jumping to contribute significant effort to the project, whereas the Mozilla team inevitably has solid answers about maintenance costs bashing their decisions.