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

Yes, PEX is the flexible tubing material you are thinking should exist.

PEX and sharkbite fittings are like magic - you can plug together arbitrarily complex water circuits and layouts as simply as building with legos.

I personally use copper piping for very long-lived installations and for simple, long runs. However, anything complex at the end of the line (irrigation, pump and well work, filter assemblies, etc.) transitions to PEX and shark bites.