"...At the moment you cannot find out what your contention ratio is. The average used to be 50:1 for home customers and 20:1 for businesses, but improvements to broadband infrastructure have rendered these figures obsolete...."
Ah - I see what you're thinking. The statement that the figures are 'obsolete' refers not to the fact that speeds have increased, but to the fact that these ratios used to be fixed. For all modern networks they are now dynamic, which is why you cannot 'find out what it is'. It is changing all the time. But the number of signals multiplexed into each channel is still a factor in the bandwidth you will obtain.
Dynamic contention rations are set by algorithms, and modified on the fly by humans with knowledge of the likely load. Mobile phone bandwidth, for instance, would be increased considerably around Wembley during a Cup Final. Extra mobile Base Stations are put in place during events like Glastonbury to maintain adequate service. So contention ratios are not 'just statistical planning tools' - they really have an effect. If you monitor your service throughout the day you should see the network 'breathe' - expand and contract as the load comes on and off it. Unless, I suppose, you are on a link which is kept at a static high service level for Emergency Network purposes...
"...Bad luck with your connection DG ☹️...."
I'm not unhappy about my connection - it's likely to be as good as fibre can make it. The point is that I have considerable local contention, since I run several web servers and other services through the same connection. Anything I measure on my local browser is affected by other computer users in the building, external phones
using the local hot-spot and, of course, people browsing the web pages or downloading. I could only get a 'best service' reading by closing all this down - which would make the kids and wife unhappy, at the very least... :( Though it might save me a fortune on internet purchases of dresses