This is a fantastic thread. Amrgolis post is full of some great ideas.
We are about a year behind you in building a new house (will start construction summer 2021). This is the second house we have built (well last one was a gut renovation 13 years ago).
Current thinking for the newbuild (although things may change so much in two years, will wait as long as possible to pick actual electronics)
1. 2xCat 6 and 2xRG6 pulled to every room.
2. Cat 6 pulled to ceiling of every room.
3. Cat 6 pulled to doorbell and potential outdoor camera locations
Network: Unifi (Ubiqiti) Network -- UDM Pro, Unifi APs
Whole House Audio: Sonos One/SL or Sonos 5 speakers in all rooms where we want audio
Phone System: None (no landline; cell phones only)
Intercom: Amazon Echo dot w/clock or Echo shows in all rooms that need intercom
Main TV in great room will be large QLED (bright room) with Sonos Arc + sub
Den and MBR will have large TCL Series 6 or 8 with Sonos Beam
Inexpensive TCLs for guest rooms
If YoutubeTV has improved picture quality and added 5.1 will use that for TV, otherwise if Tivo is still around will likely use that for cable TV plus Tivo Minis for other TVs
Lighting: Lutron RadioRA2 (+ blinds)
Smart Thermostats: Nest
Security System: SimpliSafe
Security Cameras: Arlo doorbell and Arlo Ultra Cameras
Smart Door locks: August WiFi lock
Smart Garage Door: TBD
I am very comfortable with setting up hardware/software, not so much with drilling holes, snaking wires and mounting things.
Not planning on trying to integrate all this stuff (a la Crestron or Connect4) -- perfectly fine using different apps for each system, plus Alexa voice control and maybe some IFTTT. Allows for upgrading each system as desired, without having to spend a fortune on the system integrator rewriting code each time.