For any wired devices you need Cat 5e or better to benefit from the 1gb speed and Cat 5 only supports 100mb so ideally only about 70-80mb. Ethernet extenders are the same, they usually only support 100mb also and Smart TV's usually only come with a 10/100 network card, so again 100mb, 80mb reality.
If it were me I'd get a third party router and put the hub in modem mode, something with wifi 6 for better speeds and connectivity. I use 2 x Asus wi-fi 6 routers set up with Asus AiMesh system and get excellent speeds and coverage all around the house ranging from 400mb on my tablet and 830mb on my iPhone 11 Pro Max, but never any less than 400mb at my furthest point from any of the routers. I have one router at the Hub 4 and a single Cat 6 cable running upstairs to the other router but you can use these via wireless as well and most of my devices connected via wireless. My main PC in my living room is wired, my DVR, TV, NAS and printer are all wired using gigabyte switches and everything else is wireless (5Ghz) and Smart plugs are 2.4Ghz as that all they need. I try to keep everything wired where possible.
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Super Hub 4.0 (modem mode) - Gig1 Fibre FTTP - Asus RT-AX82U & Asus RT-AX56U with AiMesh setup
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