How about some basic details on your current ASUS router? How have you confirmed that your router is the problem? Have you actually gone through the process of mapping out your home's WiFi coverage?
Unless you have at least a simple analysis of your WiFi coverage it could be a matter of just repositioning or relocating your ASUS router. Buying a new router and setting it up in the same way could just result in the same problem occurring. Or not given a good router with multiple antennas will out-perform an older, less capable router. So again, what model ASUS router do you have?
If you have an Android mobile device, try using this 'WiFi Analyzer (open source)' app to make basic WiFi heat map of your home:
https://play.google.com/store/apps/details?id=com.vrem.wifianalyzer&hl=en_US&gl=US&pli=1
Stand a few feet in front of your ASUS router to get a baseline measurement (check both 2.4GHz and 5GHz), then go to different locations in your home and get some WiFi signal strength numbers. Using actual, numeric data to make educated decisions are better than just assumptions and guesses.
You might be able to fix any weak spots by just focusing on where you have your router set up:
https://arstechnica.com/gadgets/2020/02/the-ars-technica-semi-scientific-guide-to-wi-fi-access-point-placement/
If your ASUS is too dated as an adequate router, I'll just tentatively suggest this TP-Link AX-21 router:
https://www.xda-developers.com/tp-link-archer-ax21-70-deal/
This is a budget-class router but I picked one up several months ago and it's a very capable router.
But a lot of your choice in a new router should also involve just how big is your home? Something like this AX-21 should work out well in a relative small home but if you have a substantially large household, with multiple users, you might want to look into upgrading into a mesh WIFI setup. Generally, if your home is over 2300 sq. ft. in size, a single router won't be adequate. You could get a router and then extenders, or get a mesh router/nodes that can provide a more extensive WiFi network.
https://www.nytimes.com/wirecutter/reviews/best-wi-fi-mesh-networking-kits/