What happens when it’s just not profitable to mine?

I’m a bitnoob. I buy 10$ of bitcoin every two weeks, sorry if the answer is obvious.

From my understanding, the system works because millions of computers are processing calculations while being awarded bitcoins, this is what we call mining.

Transactions go through because there are people mining bitcoins. The thing is, there are less and less bitcoins to mine as we approach 21 millions.

Aren’t we eventually going to be in a place where it’s just not profitable to mine so no transactions are going through?

I know the number of bitcoins awarded decrease at certain points, but the cost of mining will become to high.

Only way I can see all this working would be the price of bitcoins increasing enough so that the infinitely small amount of bitcoin awarded is enough to be profitable, which would benefit all holder. Is that what everyone is betting one here?