I is multiple routers for a number of reason. I also use the routers in wired bridge mode.
A 5G signal gets downgraded every time it passes thru a wall or window. In a wired bridge mode setup I get 1G to all the devices that I hook up to each router and my wifi signal is the best it can be because of no walls.
For example, my wifi signal was very weak on the back patio so my grill wouldn’t connect to my wifi, same goes for my 2.4 devices in the garage.
If you setup a 2nd or 3rd router in a wireless bridge mode, your wifi signal in the surrounding are of the 2nd router, your speed will only be as fast as the 2nd router. I always go the wired route

Fixed my router issue
 

Had some coverage issues with my Century Router. 4 TV's, 3 Computers, 2 Smart Phones, Alexa and "Love Lamp". Relocated my router into a central location and everything works perfectly. Did not require an electrician, handyman or CenturyLink. Just see 2 new switch plates.