I have been using fuel additives including fuel treatment as well as fuel injector cleaner etc in my car and truck for years and yes those fuel additives added to the gasoline tank do really work great.
You should add fuel additives or fuel injector cleaners to your gasoline tank after every second fill up and they will keep your engine running very smoothly.
The fuel injector cleaner helps to clean partially clogged fuel injectors and helps to prevent the fuel injectors from fully becoming clogged.
If you're noticing hesitation, or stalling then your fuel injectors could be partially clogged and sometimes adding some fuel injector cleaner to your fuel tank will help get the injectors cleaned enough to get them going good.
Sometimes when I notice hesitation or sometimes stalling I'll add a bottle of fuel injector cleaner to the engines fuel tank and it clears up within a few miles of driving.
If not then you'll need to have your fuel injectors professionally cleaned or replaced.