Probably, you are forgeting that one Bitcoin represents 100 million indivisible units.

21 million coins - it's just over two quadrillion (2099999997690000) of the maximum possible units.

It is assumed that by the time when the last Bitcoin is mined, the parts of the coin will be in circulation - millibots (mBTC) and microBit coils (μBTC). However, a denomination with coefficients of 1:10, 1: 100 and so on is also possible.

So it will take less than 100 years to reach that total supply, we are not even going to be alive to see it happening, if bitcoin would be still alive too..
There is no need to worry about, and those forked coins, are not even going to be a live for the next months, they are a fail, bitcoin cash was the only good one of them.