I live in a semi-rural area. There's no utility gas near me; we're too sparse for that to make sense. I'd guess most of the houses have big propane tanks (i've got two 250 gallon tanks) and there's several different companies that will come out and fill the tanks. In the nearby urban area, there's utility gas, but then they're trying to outlaw that for indoor air quality reasons.
I don't have utility water; it's available on my street, but it doesn't run by my house, it stops at a much lower elevation, our well water is fine (although we had to replace the well pump recently which was expensive). No utility sewer either, that's available in parts of my area, but mostly places with density or poor site conditions for septic or both.
Electricity is mostly overhead, with a little bit of underground telephone has a lot of undergrounding, but some overhead, cable and municipal fiber are almost all overhead. But when those are undergrounded here, they're on the sides of the road (directly under the overhead path) not under the road. That way it's easier to get to them for maintenance when needed.
Over their lifetime, easily. The pipes for those will last 100 years, easily. The maintenance of them are paid for by the delivery costs you pay in your bill.
As for rural I think there's 2 distinctions. 1 is we need rural communities because they produce our food and other things. Secondly, rural areas are between 2 or more populated areas. We need to connect populated areas so by necessity there are roads. Rural communities are built off of those.
The other distinction where you may be closer is exuburban communities built into rural areas. These may or may not be fully covered. Not initially anyways, but you'd assume the property taxes would cover in time.
My wife served on a sanitary district board. Decent underground sewer mains have an expected service life of 70 years. Some will last longer, some won't hit the expectation. It depends on site conditions, materials, etc, etc. Many will probably last to 100 years, but I wouldn't expect it to be easy. Especially if you had any of the not decent materials (Orangeburg pipe was common in some areas and is basically wood pulp/fibers mixed with hot tar; service life could vary between 10 and 50 years; the major manufacturer went out of business in 1974, as PVC and ABS pipes rapidly replaced Orangeburg in the materials markerplace).
Actually there was a huge nationwide boom in sewer building post WWII, especially in the 50s, and you can expect that infrastructure to need some largescale replacement over the next 20 years or so. Depending on system design and how housing and industry developed, some systems will be able to just inspect periodically and replace as needed, and some systems will probably take the opportunity to do a more modern redesign (older cities tend to have combined sanitary sewers and storm/runoff drainage; if you're tearing up all the streets to replace the sanitary sewer, it might be a good time to put in a parallel storm drain system)
I'm not sure about water mains, I'd guess they need more frequent replacement since they operate at pressure.
