I only recently bought my first oscilloscope (Telequipment analog CRT scope circa 1964), but I've done electronics for years without one. Mostly audio stuff so

I only recently bought my first oscilloscope (Telequipment analog CRT scope circa 1964), but I've done electronics for years without one. Mostly audio stuff so I've poked an audio probe in the circuit and listen to the signal rather than look at it. So no, it's by no means essential but it certainly opens some new doors in the hobby. If you want to build kits, say for guitar pedals (pretty popular electronics-related hobby), you can manage without an oscilloscope. But for designing experimental circuits from scratch, it's really nice to have one. And it's just fun to play your guitar with the signal plotted on the warm glowing cathode ray tube.