Is Bitcoin truly fungible? This is the only bit I'm not entirely sure about, because all transactions are obviously on a public ledger, so for instance if I had 1 BTC that I withdrew from SR and 1 BTC I bought KYC'd from Coinbase say, I wouldn't call those two coins interchangeable.

If I try to spend the first coin, feds are gonna be watching every movement from that wallet.

If I spend the second, since it's KYC it links my tx's back to me.

There are obviously solutions for this (e.g. tumbling, coinjoin, LN) so it's not necessarily a problem with Bitcoin itself, but it is with on-chain transactions.

Maybe I'm just nitpicking a bit but it's something that's been stuck in the back of my head for a while.

Bitcoin fungible? I call that marketing at best or propaganda at worst.

There's a place for truth, just as there is a place for Bitcoin and Monero.

Gold is divisible to the atomic level

Also where's the box for "physically exists" ?