Installing tiles requires more skill than asphalt.
In California, because of clumsy rules around workers compensation insurance, low-skilled high-risk labor is much cheaper than high-skilled labor. As a homebuilder explained it to me: if you hire actual roofers you have to pay very high insurance rates (roofing is quite dangerous). But if you hire day laborers and tell them to install the roof, you don't. So they prefer roof designs that day laborers can install.
Installing concrete tiles requires pretty much no skill. Anyone could do it after watching a 20 min youtube video. They literally just interlock and hold each other in place. You only need to nail down edge ones. A whole roof can be done in a day by 2 people - and most of the time is spend hauling the tiles to the roof - they're heavy!!
Florida has a lot of houses with tile roofs. I think Arizona, New Mexico, and Texas also have lots of places with tile roofs due to the Southwest aesthetic.
As an Australian who has moved to the USA, I don't know why it's done. I don't know a single person in Australia who has ever replaced their roof. My dad lives in the same house I was born in 40 years ago, same roof. I've been in Colorado for 4 years. We had a new roof put on 2 years ago, then another 6 weeks ago due to a bad hail storm.
A quick search suggests that it's because historically clay tile roofs didn't do well in environments that regularly drop below freezing (like Colorado). It sounds like newer materials can handle freezing weather fine, so our usage of asphalt probably is just a cultural habit at this point.
I did find it super weird the first time I heard of Americans using asphalt shingles. Everything over here is either corrugated steel (often powdercoated) or tiles, apart from some fancy upmarket properties with zinc roofs.
As child poster notes, the weight is a factor, and US houses uses wood frames for construction, where warmer parts may use brick construction. Can carry heavier roofs.
My house is wood frame, brick veneer. It was relatively cheaply built government housing back in the 40s/50s. It seems to have held up just fine with the weight of concrete tiles.