Prior to the 1980s I dont recall even seeing Ball Valves. If they were
made, they were not common. Every house I lived or worked in had a gate
valve for the water main shutoff, or heaven forbid, a washer valve. The
washer valves simply did not hold up as a main. But the gate valves
seemed to be the most popular. While they worked, they were a pain to
operate. Seems they always need 20 or mre turns to shut them off, which
is really bad if there is a broken pipe that needs to be shut off NOW.

Anyhow, I moved into my house about 14 years ago, and I replaced a lot
of the plumbing, including adding a main (gate) valve in the house,
because before that, one would have to go outside to the well pump house
to shut off the water. Last week I shut off that garte valve to do some
repairs and it would not shut off the water completely. There was still
a trickle. I would not have expected that from a 14 year old valve.

I just replaced it with a ball valve. A local plumber said that gate
valves are obsolete, and to always use a ball valve. Well, anything can
get bad over time, but I am wondering if ball valves have a longer life?
My well water is hard, but does not contain sand or grit and is not
acidic as far as I know. Why that gate valve leaks is beyond me. After
removing it, it does not appear to be worn, but there is some corrosion
inside. Of course that can be expected on brass.

Are ball valves used exclusively these days for water mains?