Are pagers free to use (i.e dont need to buy credit to send messages?) if so why dont more people use them?

ok pagers have no range a text will reach you anywhere or should i say a page? no they do not charge you for each msg you send or recive doctors still use them since the pagers dont really need a tower to send a signal so its more reliable than a cell phone beepers or pager service fees are as low as 1.99 us.