I recently bought a cheap&small office laptop with intention of taking it with me and completing assignments in public places. Problem is, it chokes up and dies when running more than eight tabs on firefox. I also tried k-meleon, it has great performance but the UI is ancient and many websites that I need dont support it.
You can’t escape the bloat of the modern web, you could disable javascript on many browsers like firefox but it will break many websites and thats what happened with that browser you installed. Maybe go for librewolf?