(I’m assuming you’re in USA)

The other commenters have correctly described how you could run metallic conduit (EMT) or PVC, and that would be perfectly acceptable for “low voltage” wires like twisted pair Ethernet. But it’s also kinda overbuilding it, because EMT or PVC are also suitable for “line voltage” AC electricity. Other conduit types are available, depending on your jurisdiction, since EMT is meant to provide physical protection and PVC is meant for be water-resistant. And both provide physical support for the wires within. None of these qualities are really required for Cat 5/6 cabling.

Here in California, it is permissible to use ENT – with an N – also known as Smurf tube for its blue color, for line-voltage applications where no environmental protection (physical, UV, vibrations) is required. Smurf tube is made from thin, corrugated plastic in standard sizes, so it’s easy to pass through top-plates and anchor to studs. This makes it an excellent choice for organizing low-voltage wires, or for future proofing.

Indeed, if you really wanted to, you could terminate the Smurf tube into standard outlet boxes, so that there’s zero exposure to the insulation batts within the wall, for when you later fish the cables through. For a still-acceptable arrangement, the Smurf tube could be anchored just above where you’ve cut out a hole for the future wall-plate, allowing retrieval of the cable through that hole. You should not later use these conduits for AC electricity though, and mixing low-voltage and line-voltage in the same conduit or box is typically prohibited.

I do think that conduit is true future proofing. Who knows if CAT6, 7, or 8 just gets replaced (finally) with fibre optic cables. Or perhaps you decide to become a ham radio operator and thus need to run specialized coax. Or maybe you really want a 50 ft HDMI cable from the upstairs living room down to the man-cave in this basement. Running wire today is temporary, but conduit is forever haha.