Very useful as a currency, many people use it. Not to buy a snickers, but to easily and quickly transfer large sums of money.

Yes tether is useful for moving and storing the dollar equivalent value. The system works for many people and companies everyday. That's why it's growing.

Easy one - A less safe way to hold money in an active war zone is to hold it physically. With crypto you can hold the keys in your head.

Bitcoin system and protocols is open source. No one company controls it. That's not even a debate.