I used DD-WRT and OpenWRT for a number of years. They are something of an upgrade, but are more about flexibility and custom configuration rather than security or reliability per se.
About 3 years ago I got rid of all of the consumer stuff for routing and wifi and went with Ubiquiti. Best move I have ever made. I spent about 4-6 hours learning the system. I now have 12 wireless access points spread over our family farm (3 houses, a barn, swimming pool, outdoor areas between them) with continuous wifi throughout the area. One of the homes is over 1800' from the router; this is not even an extreme case for the system.
The router has been up and running 802 days 11 hours continuously with no down time. Security updates or configuration changes are done on the fly with no interruption of wired or wireless service. The wifi is a hybrid of wired and wireless / mesh, so if an access point goes down, wireless devices just have to talk to another access point over slightly longer distances. I get a notification, and fix the problem. I had one access point just die, they mostly get unplugged accidentally. Lost one pressure washing the house. To add a new node, I just plug it in, wait about 5 minutes, open the app and provision the access point, and it's done.
Before doing this change, I was tech support for internet access for the three families on the farm and got lots of calls for help.
If you don't need something as extensive, their Amplifi system is great for access in one building. Mesh satellites ensure great wifi throughout the home.