No, in general there is no prepayment penalty. In fact, it is relatively rare for a 30 year mortgage to last the entire 30 years. Normally it is paid off early, either because the person sells the home and moves somewhere else, meaning they pay off their old mortgage with the proceeds from the sale and get a new mortgage for the new house.

Or, you "refinance" your loan for a better interest rate after you have paid down the loan some. For example, I bought a house in 2018 and refinanced in 2020. Since my home price has gone up in those two years, and I had also paid some of the mortgage off, my rate was much better since my loan-to-value ratio was lower (basically the percentage of the market value of the home you are borrowing... the lower that is, the less risk the lender is taking, since they can sell the house to get back more than the cost of the loan, therefore it has a lower interest rate) I was able to save a large amount on my payment (went from paying $4700 a month to $3600), although it did extend the term of my loan for an extra two years. However, I doubt I'll be in the house that long anyway.