You missed some good stuff. And, if you are going to pick up stuff like that, learn to fix some of it. Those other speakers were powered speakers. Good for people who want to practice guitar at home and then take the speaker out on the road or just anyone who needs them.
I think that box with that psu looking thing with the black and yellow cables was something related to crypto-mining or some server gear. Sometimes I see things in these vids that I would take but it is your choice. I have usually never been as lucky as you when I go diving
