The Al foil provides 100% shielding, something harder to achieve with braided copper (or whatever), so that is a good thing. To achieve similar shielding with braids typically requires dual wraps, two layers wrapped at right (90 degree) angles, so make the coax thicker. You can buy RG-59 variations in a wide variety of types having different flexibility, shielding, etc.
For cables that are frequently flexed, the foil can develop splits and tiny openings, so in those cases (which includes interconnects that are fairly frequently moved and pro audio cables used for live sound) braid (and stranded center conductors) works better for longevity (not necessarily for shielding but the good ones are 98% or better). I have a bunch of mic and instrument cables that use thick but flexible outer layers, braided shields, foamed poly or similar flexible inner dielectric, and stranded center conductors. And some less-flexible but better-shielded patch cables for the rack since they are not usually moved and (rarely) stepped upon. At work we have fairly standard RF cables, some with armor to withstand abuse during handling, and some gorgeous very thick yet very flexible lab standard cables that rival some audiophile cables in expense ($10k~$20k for 1 m). Since it is a noisy environment foil shielding foil shielding is common but with a full braid for reliability. I have seen cheaper cables using foil without, or very little, braid but those are not meant for day-to-day lab use.
Flexibility is a function of many things, including the type, number and thickness of the shielding, type and thickness of the center conductor, type of dielectric (insulation inside), and type and thickness of the external sheath (insulation on the outside plus any additional armor). You can buy RF cables in a huge range of flexibilities from small coax that behaves like a thick floppy string, so a range of standard coax from flexible to very stiff (some cables are armored, i.e. include a semi-flexible plastic or metal protective layer, to guard against abrasion and excessive flexure), to semi-rigid that is basically bendable conduit (metal tubes), to hard coax that is like thick pipes.
BTW coax describes the construction: a center conductor with cylindrical insulation layer and outer cylindrical shield layer, with perhaps an outermost insulating layer for protection. The vast majority of audio interconnects are coax in nature, including pro-grade audio cables, exceptions being the twisted-wire and flat cable some manufacturers sell. Speaker cables are usually twin-lead (zip-cord) cables.
FWIWFM - Don