Imagine a world before computers.
Imagine making records with only 4 or best case 8 tracks. Imagine life where a performance would be captured on tape and never edited, tuned or manipulated on a DAW.
Imagine standing in a recording studio the size of your bedroom, with a tape machine the size of a refrigerator and a console with huge knobs and a guy wearing Ray-Bans and smoking a cigarette while he's turning them.
Now look to your left. See that big wooden crate in the corner? That's a plate reverb. That is the sound of music from the early 50's through the 80's, all 6ft and 400 lbs of it.
There is no reverb but plate reverb.
Well, spring reverb is a very close second. Everything else is just an algorithm.