You should consider upgrading to some kind of mesh system then. sure they aren’t perfect, but even a basic 3 node kit could probably increase your throughput ten fold. If you want to use DDWRT or OpnSense or whatever you can still run it separately and route internet traffic or use it for your DHCP server.
To stream a 4K bluray remux rips on your Lan you need a solid 150mbit minimum between server and player to be reliable for example. I am hardwired all the way except for mobiles, but even on Wi-Fi I can easily pull 400-500mbit real world throughput through most of the house thanks to my Wifi6 setup with multiple APs