7 is not busy, I can see 10 on a good day, and 15/20 on a bad day. I have friends whom live in other blocks whom can see 40+ networks. That is busy. (And a friend whom lived in a high rise in New York City was unable to use WiFi, used to have a 40ft ethernet cable into her laptop. This was back in 2012. There were more than 100 networks, and WiFi G technology collapsed).
If I counted everything, there would be more than 7, but some comes from the same router, like Bt ones have their BTwi-fi. Saying that I have just looked again and there is something called BThomespot, never seen it before, had a quick search, and it is a Wi-fi extender. If I count everything my phone is picking up, then there is 18, but as I said, some of them would be from the same routers.
I expect in parts of New York City and even in places like Birmingham and high rise flats, no high rise flats here, there are some maisonettes about a 2-minute walk from here, but that is it. We don't have any high rise flats in the city, I think the tallest is around 4 floors.
Oh
, this is the tallest and this is student accommodation, for some unknown reason. 40 foot Ethernet cable, wow, that is a long cable, surly there must be some loss in that, even with modern higher quality ones there would be a fair bit of loss in that length.
I had a Zyxel for a while on VDSL/FTTC but it was a thin flat box, with no visible antenna. Pretty much useless for WiFi. I assumed Zyxel was not a brand for WiFi, and turned it off. I'm now on VM cable due to crosstalk on VDSL, and I use my WiFi 6 ASUS router which is 2.5 years old now.
My zyxel is a flat box that stands up. I did think about Asus, before I tried the combination I have now, but I really did not want to spend money on something that would be replaced if I did go for FTTP as I was pretty sure at the time I would go that direction.
I could ask plusnet for a new one, but again, I did not think it was worth it for 18 months.
To be honest, I am surprised this TP link is working so well, I got it when I went for a Wireless broadband service a few years ago, over 9 years ago i started to use that. But to be fair it has been sat in it's box for a good 5-6 years.
No updates for it now, there is a newer version of it, mine is Version 1, I think they are on version 3 now. The antennas do annoy me a little, they don't make the router much good for wall mounting

at least the Zyxel could wall mount fine.
Older low bandwidth devices (e.g. echo dot, wifi plugs) did this, but all the latest versions (2018/19 onwards) include the 5GHz band because of congestion.
A lot of smart home devices still use 2.4Mhz for some reason, I just had a look to see what the Echo dots use and yes mine does use 5Ghz as well as 2Ghz, I wonder if that is why they used to play up with the Zyxel router in place, I had a lot of the can't connect to the internet errors, I have not had any since I changed to the TP-link.
I did change the name of the SSID to something I can use if I changed routers, trying to connect all the plugs and stuff when I changed router was a pain in the neck.

My Philips Hue and my thermostat thankfully use Ethernet.
a lot of smart plugs still use 2.4Ghz.
You have to plan how to use it, doesn't mean the technology is useless. It is significantly less range and is stopped by metalwork in some walls, but due to this the increases in capacity are significant. You can already buy hardware that uses the 6 GHz band using WiFi 6 (AX) protocol, this is known as WiFi 6E. You ask why? Becuase people want to get gigabit speeds to their laptops and desktops across homes and offices without wires.
But it is no good if the signal can't get through a wall. This house is pretty solid with brick walls, built around 80 years ago or more.
5Ghz signal is much weaker.
My corporate has essentially removed Ethernet everywhere, we no longer have desk phones. Everything is WiFi, and we have mobiles or use phone features on laptops (e.g. MS Teams). We used to have 100 Mbps Ethernet each, now most people get 200+ Mbps on WiFi using WiFi 5, and they are hoping to upgrade the infrastructure to WiFi 6 / 6E soon. We keep our laptops for 4 to 5 years, and I've just had my WiFi 5 laptop replaced with a new one that supports WiFi 6.
Where I work, most is wi-fi and have been for years as we use hand scanners, it was around 4 years ago that it was updated and also a public Wi-fi system added, i don't know what it uses as I don't use the Public wi-fi myself, it is run by O2 and to be honest is not that good. The network that the handset uses is not o2, that is a corparate system. the computers are printers are still Ethernet.
My WiFi reaches into my neighbours flats, so er, yes. I can pick up the bluetooth of my neighbours Samsung and OnePlus phones when pairing my headphones. And I live in a 1970s built block, we don't have the late 1980s "paper walls", so I can only assume things are worse for many others.
It takes a bit of doing to hack WPA2 surly. I can pick up something called LG-PL2 on my bluetooth and my next door neighbour's Samsung TV. We have thick walls as well.
Yes, no need to upgrade if everything is working. I think we made a mistake in the UK in not having the domestic hardware supplied by the network operator (e.g. Openreach, CityFibre) but being supplied by the ISP, which means we are creating a lot of e-waste.
When FTC started, we had a standard modem supplied by Open reach, it is a pity they did not do the router either, but I suppose different providers want to add their own services. It is providers like BT that seems to give out routers like sweets, oh you signed up for another 18 month, lets give you another router.
If I changed to zzoomm, they will give me two router type things, l plus the thing on the outside of the wall, not that I am likely to change to zzoomm.
Adrian
Desktop machine Ryzen powered with windows something or other.
Plusnet FTTC