Yes, it is. They are not introducing BTC into circulation. This is verifiable via the blockchain.
Banks creating IOU's or derivatives or whatever other abstraction they can come up with never generates new BTC. You'd hope that people foolish enough to work with such financial institutions would know the risk of possessing nothing but an instrument created by the bank. If you're unwilling to take custody of your own bitcoin, you better damn well do some good research on third party custodians.
How much BTC exists in the blockchain is ultimately irrelevant. What matters is the amount of BTC actively circulating.
If you deposit 1 BTC on Binance, then I can get your BTC in the form of a loan. I can even withdraw your BTC. Meanwhile, Binance records still say you have 1 BTC, they even allow you to trade with it. So there's really 2 BTC in circulation. That BTC is duplicated, it's in multiple places simultaneously.
That is correct. And, fundamentally, this is possible because the Bitcoin chain is not the only ledger out there tracking BTC. Each (centralized) exchange has its own internal ledger, tracking how much BTC its customers have.
Yes, it is. They are not introducing BTC into circulation. This is verifiable via the blockchain.
Banks creating IOU's or derivatives or whatever other abstraction they can come up with never generates new BTC. You'd hope that people foolish enough to work with such financial institutions would know the risk of possessing nothing but an instrument created by the bank. If you're unwilling to take custody of your own bitcoin, you better damn well do some good research on third party custodians.