Easy pathway here. Enjoy it as long as you can. "Don't worry, be happy." Your kids don't want it. Fine. You can't keep it. So, fine again. Be useful with it after you can no longer use it your self.
My kid listens from his phone through cheap earbuds. He's happy with his apple music and spotify - and I'm happy to see him happy with it. And grateful when he wants to share a tune or two. He has other ways to spend his time for fun beyond fretting over what wire might sound better....that's MY kind of fun!
"It" (your collected goodies) can still be useful when it's no longer useful for your enjoyment even if transformed into something else.....like cash. Sounds like you probably have an estate executor (I'm guessing here). I've seen gear auctions as part of an estate plenty of times. Just leave directions in your will and have your lawyer or audiopal or whoever take care of it for whatever cut they want if you're in some other environment. Make a list of what you think they're worth - should be pretty quick and easy. Especially if you keep in mind it doesn't matter since you'll be dead and your kids don't care.
It seems pretty solvable and definitely not worth fretting over. It's just stuff afterall - BUT, it's stuff that can benefit somebody or organization.
Keep it simple - what's the beef here? Why not donate the music to a a school or library? Or a nursing home? They can keep what they believe others will enjoy and sell or discard the rest. Same with your 100K system - have the executor auction or sell it off and give the money to an organization or entity that is in need an desire and wants to (and will) make use of your unwanted things.
For crying out loud.
And, if nobody wants your guns, break them into little useless pieces. You never know, you might save a life.