Bitcoin isn’t infinite but Bitcoin value is, if you control the market of Bitcoin(you have a lot of it) you can control the offer and demand of it selling or buying big amounts, that way you can add or quit 0 WO having to modify the amount of bitcoins on the market. As it is a divisible currency you can always buy or sell fractions or units of it, so it doesn’t matter how much Bitcoins are out there the important thing it’s the value.