It’s hard to convey how invaluable an oscilloscope is for most electronics labs, at least when you reach the point where you're dealing with your own designs and/or troubleshooting others' flaky designs. Not for use all the time, but for being there if needed. After all, signals in electronics are everywhere, and being able to see a represantation of them takes out so much guesswork from any situation.

You don’t technically need one, but that’ll make a lot of work much harder and some work impossible.