@David09 - Here’s an interesting bit of trivia. The first computer ever invented was made entirely of cathode ray tubes. It was the ENIAC computer, built around the late 1940s I believe, and had stacks and stacks of cathode ray tubes to do its processing.
This was before the transistor came on the scene. Imagine a computer made up of thousands of tubes. It’s like wiring your house for Christmas. One tube goes out and you have to track it down and replace it, otherwise everything won’t work right.