We have better consumer protection laws in Australia.
Apple behave differently in different markets. Here they have come to the attention of consumer authorities any number of times for ignoring local regulations.
I really do not know what the situation in the US is like..
I have owned a number of Asus routers or bought for friends.. all are doing well.. I am running a much older one at the moment. RT-AC3200. Another model did have issues on my connection.. but it was a combo of ISP setup and a particularly poor installation. Technically I doubt you will have issues.. if their warranty issues preclude you buying them.. pick one of the other brands.
NOTE Apple routers have never worked on my connections.. They use PPPOE standard that does not comply with my ISP. I tried many version and many firmwares.. so all routers do give trouble on some connections. There are just too many flavours of internet connections out there. I also have used (and repaired) many of the Apple routers. Some of them were terrible.. the early Time Capsules were shockers and Apple refused repairs or replacement outside 12month warranty by even a few days and that was for a $400US product. Many died at 18months. They did finally extend warranty but only after most people had already disposed of them.
Applecare is an add on service.. which you pay for.. and it reflects in the cost of the products.. certainly Apple have phone support etc in US. They are not so great here. Note that Applecare has never been available for purchase on apple routers.. but they were covered as periphrals on computer, iPads and Apple TV.. although the rules changed a fair bit.
Ubiquiti is a US company and I am very happy with products. If you are prepared to learn the interface and systems then they work very well.
Synology is also a good option to try but you will need to check their US situation. They should have a big presence as they sell large numbers of NAS devices for which they are better known.
Certainly in terms of firmware advancement the products I listed are far ahead of the average. Plus working with Apple functions like bonjour.. which not all routers handle at all well.