Most materials will not last long in water, especially hot water with the various chlorinated organic compounds that result from sterilizing impure water with chlorine. Copper and CPVC are really rather special! Gaviotas had to replace the pipes in all of their aluminum-piping rooftop hot-water heaters with expensive copper when it turned out aluminum could handle chlorine but not the municipal water at their customer sites. All over the US, polybutylene piping turned out to only last about ten or twenty years due to unforeseen issues with chloramine corrosion of the PB pipes and Delrin pipe fittings, but only where they're under stress. And that's why you can't buy polybutylene pipe anywhere in the US since 1995.

And it turns out that an unexpected rupture of a water pipe can be very, very expensive indeed. Especially in a wood-framed structure with sheetrock. Especially if nobody's home.

So builders are generally very conservative with water pipe materials. Nobody wants to install the next PB disaster. Building supply companies are even more so; the PB lawsuit cost Shell a billion dollars.

Garden hoses are usually made from one of two materials: some kind of rubber (buna?) or PVC plasticized with phthalates. With hot water, neither of these will last even the 10 years that a lot of PB piping lasted, and the phthalates will leach out into the water and give it that garden-hose taste.

I don't think the curviness of hoses is generally enough to cause a significant pressure loss.

As noted in another comment, PEX is sort of flexible and hoselike, and is seeing a substantial amount of use for water piping nowadays.