Selfhosted

My Linksys router died this morning - fortunately, I had a spare Netgear one laying around, but manually replacing all DHCP reservations (security cameras, user devices, network devices, specific IoT devices) and port forwarding options was a tedious pain. I needed a quick solution; my job is remote, so I factory reset the Netgear (I wasn't sure what settings were already on it) and applied the most important settings to get the job done.

I'm looking for recommendations for either a more mature setup, backup solution, or another solution. Currently, my internet is provided from an AT&T ONT, which has almost everything disabled (DHCP included), and was passing through to my Linksys router. This acted as the router and DHCP server, and provided a direct connection to an 8-port switch, which split off into devices, 2 more routers acting as access points (one for the other side of the house, one for the separated garage, DHCP disabled on both).

If going the route of a backup solution, is it feasible to install OpenWRT on all of my devices, with the expectation that I can do some sort of automated backups of all settings and configurations, and restore in case of a router dying?

If going the route of a smarter solution, I'm not sure what to consider, so I'd love to hear some input. I think having so many devices using DHCP reservations might not be the way to go, but it's the best way I've been able to provide organization and structure to my growing collection of network devices.

If going with a more mature setup, I'm not sure what to consider for a fair ballpark budget / group of devices for a home network. I've been eyeing the Ubiquiti Cloud Gateway + 3 APs for a while (to replace my current 1 router / 2 routers-in-AP-mode setup), but am wondering if the selfhosted community has any better recommendations.

I'm happy to provide more information - I understand that selfhosting / home network setup is not a one-size-fits-all.

Edit: Forgot to mention! Another minor gripe I have is that my current 1 router / 2 routers-as-AP solution isn't meshed, so my devices have to be aware of all 3 networks as I walk across my property. It's a pain that I know can be solved with buying dedicated access points (...right?), but I'd like to know other's experiences with this, either with OpenWRT, or other network solutions!

Edit 2: Thanks for the suggestions and discussion everybody, I appreciate hearing everybody's recommendations and different approaches. I think I'm leaning towards the Ubiquiti UCG Ultra and a few Ubiquiti APs, they seem to cover my needs well. If in a few years that bites me in the ass, I think my next choices will be Mikrotik, OPNsense, or OpenWRT.