Ethernet uses two balanced pair (Rx/Tx) per port using up all 4 pairs per cable.
POTS Phone use one balanced pair per line with two landlines using two pair.
So you can have 1 of each or both of either type..... or only 4 POTs phone lines in theory.
I have yet to see a better solution except cordless phones and high power D-Link WiFi router ( which is what I use , with care in antenna placement ) So I don't use any house wiring.
If you have hot air heating, it may be time to start hauling cables down the cold air return registers. Gentle with corner kinks. Start with dummy wire or maybe better, here's a thought, then pull an old 100' garden hose then pull the CAT5/6 inside it, to protect from corner kinks that affect Zo.
I trust you have fibrenet to support the aggregate BW. :)
It seems the future is Routers such as Orbi with MU-MIMO WiFi so a dedicated link to modem is not wasted. Then there is the hefty Eero Pro with ethernet ports on each WiFi hub.
We mainly use MagicJack to Router ( almost free phone & free LD in N.A.) , Kodi 17 addons for free web TV and free movies and an OTA antenna using HDHomerun tuner to router for local TV with 54" 1080p VGA port to tower. We have 4 grandkids with mobiles and my new DLink spread +2/-1 floors is always >-50 dBm vs the old one sometimes near -80 dBm which is a thousand times lower power. ( Single hot 3 band WiFi )
Ah yes. Need more ports and fewer octopii.
One ( 1 ) ethernet pre-wired per room is not enough, just like 3 AC outlets was normal per room but today is inadequate with all the octopus adapters. Thank goodness for 6 port USB chargers. Too bad USB power isn't included with every wall jack. My concept 10 yrs ago was central 48Vdc DC on the phone jack line2 for DC-DC adapters inside each device to get rid of all pesty little bricks. Also 48V is good for low power ambient LED lighting coming from the local battery charged from a nearby breaker panel. I suppose .