Why have dev`s made Circulating Supply so large for their coins?
Some are in the tens of billions & even trillions.
Why didn't they just follow Bitcoin at 21 million, or just limited to 100 million or so?
Because that's what they think is right. Otherwise, it's a random call for the supply limit and that's why they create millions to billions and even trillions.
The reason i ask is the price movement over $1 on some of the coins with the larger supply will always be limited. On coinmarketcap there isnt any coin out there with a CS in the billions more than $2-5 max. The simple reason is the marketcap = price x CS. Your not going to get a bigger marketcap than BitCoin for now anyway.
For XRP for example to hit $100 it would have a MC bigger than the GDP of the US, of course thats not going to happen
It's always been the supply and demand. And you're right about these coins like XRP for them to have that price, they need to have a very huge market cap.