Looking at the basic fact about the limit of bitcoin according to the protocol for the bitcoin network,it was design with a limit of 21 million coin.
My question now is are cryptocurrency miners be unable to generate new bitcoin after it reach the 21 million coin limit?
Since there are over 19.15 million bitcoins in circulation if am not mistaken.
The 21 million is the hard cap for Bitcoin mining once that amount is reached then no one will be able to mine any more bitcoins. The answer to your question is yes after they mined all 21 million bitcoins they will not be able to mine a single more Bitcoin.
In current date and time almost 19 million bitcoins has been mined so far, but you should keep in mind that Bitcoin halving happens every four years that reduces the amount of mined bitcoin to half. It is estimated by many experts that all Bitcoins will be mined around year 2140, and most of us won't live to see that day.
The next halving will take place in 2024 and with that the mining reward will reduce to 3.125 bitcoin per block and the halving will continue in that way after every four years until it reaches the end at year 2140. Just imagine what will be the expected price of a Bitcoin in that year. Those who invest in Bitcoin today would have rich generations with that investment.