I built our 1 story house in 2002, I had someone do the framing and roof. I did the inside framing, electrical, some plumbing, insulation, septic system and finish work etc. I ran
cat5e cable in all 3 bedrooms, where our TV would be and a couple extra runs to the porch and other living spaces. They didn't have much POE back then and I would like to now add some access points on the ceilings but I have 3 feet of blown-in insulation in the attic and it's impossible to get up there. I also want to run some to the edge of the house for a couple of cameras where the driveway is and luckily I can get up in the porch attic area easily. The hard part is getting into the soffits. I ran the cat5e and 75 ohm coax all to our mechanical room which is close to the center of the house.
I did run some conduit to our separate garage with an office upstairs (built in 2006) and barn. And I just ran a cat6 cable through the conduit to the garage this summer. There was a bunch of water in it! I had sealed both ends but it finds its way in somehow. I drilled a hole in the lowest part to get it to drain out. I used part of a sponge tied to a string and my shop vac to pull the string through. Then tied the cat6 to it and pulled the cable through. I had a wifi link to the garage and it was not reliable, I get gb speeds now. I have a couple of cameras (Linux based using Motion software) in the garage/office that look down at the house and driveway but are too far to pick up license plate and faces.
I also ran wire for an alarm system which I hooked up a couple of years ago. Most of my sensors are wireless but I have a couple of motion sensors and break sensors on wire. I also put in speaker wire for 5.1 in the TV area. It's nice and clean, I mounted the speakers on the wall over the wall plates . I ran speaker wire to the porch area and one bathroom but I never hooked it up.
I wish I had run more cat5e cable and some conduit in the attic for future stuff.