Every home builder does things different. Some only toss in a couple of RG6 Coax and CAT5e/CAT6 cables for Phones and call it good. Others will run Cable everywhere and others will let you do a design or select a package.
If I was to have a home built I would do this route.
CAT6 cabling at every TV location. Everyone streams these days and the few people that do use Cable-TV or Satellite attend to use Wireless boxes these days. The only time I see RG6 used is for Comcast or Spectrum comes in and installs a Modem. I would have a RG6 in the Livingroom so the Modem or main Cable-TV/Satellite box would be centralized in the home along with a CAT6 so it can back feed to a Network Switch in the main LVP (Low Voltage Panel) so all of the other CAT6 lines can be active. If it’s a main cable box or satellite box it can easily communicate to any other wireless boxes.
For the Demarc of the home I would have a 1-1/2 inch conduit going to the LVP so whoever is selected as the service provider for Internet/TV can just run a Coax or Fiber in it.
I would put the LVP in the Laundry Room. The builder I work with always wants it in the Master Closet and honestly home owners hate it there. At the time a home owner wouldn’t care until a tech has to go in there and hook up cabling. Also have another 2inch conduit going from the LVP to the attic. This makes life easier for everyone down the road if any other cable has to be added down the road.
WiFi is an issue, you never can have enough signal in a house with the Modem the service provider issues you. People that don’t know much about Networking and WiFi usage will flood their home with WiFi Extenders and have more issues. Have a WiFi Access point in the Living room close to the Master Bedroom and one in the Hallway to the other Bedrooms. If you have a two story home then have one upstairs but do not overlap with the two downstairs.
Alarm systems these days are pretty much wireless. The company I work for wires up Homes for a Alarm System but if the home owner uses a different alarm provider such as ADT, Safetouch and Vivint they won’t touch those wires. Maybe they will use one or two for powering the alarm panel. Reason being that make their money for the extra equipment they install. In Florida a legal alarm system is covering all exterior doors and a trap like a motion sensor or glass break. If you want more covered then they charge you a ridiculous amount per-sensor. If you’re offered for a Alarm System prewire I would take it but have them put it in a closet somewhere 12 – 24 inches from the ceiling. You can have it in the Laundry room, it’s all up to you.
If you want to Future proof your home I would go with CAT6a cabling. Don’t bother with CAT7 and if your builder only provides CAT5e then hire an outside low voltage company, preferably while the home is still under construction and drywall isn’t up yet.
The IT Garage 