I live in a rural area with a useless BT landline, more than 7.5km from their exchange so they can't offer me anything and anyway their line did not work for about 2 months per annum due to falling trees, wrong wind or rain etc etc. I ditched them and my life improved immeasurably!
I've been using a Three broadband router with multiple ethernet and wifi users for over two years and generally it provides speeds of about 25+ mbps down and 3-4 mbps up with a ping of about 75ms.
It used to slow in the evenings to about 5 mbps download, but is better now and has been much improved by phoning 3 Technical and them suggesting
I SET THE Huawei B535-232 ROUTER TO 3G ONLY, NOT AUTOMATIC or 4G, using the Huawei control panel. This change has transformed it's reliability and speeds. I pay about £20 pcm for this and share it around 3 properties nearby where we all watch Netflix etc successfully.
I now can't fault it.