I don't know, that doesn't seem to be the case.
With ADSL, and possibly with open access fibre in SA, there is a repeating pattern of one ISP becoming the darling of the local community. People leave their current ISPs for the promised land, and things degrade on the chosen ISP, which quickly falls out of favour and a new darling emerges. Rinse repeat. Often this seems to be due to the ISPs doing the bare minimum to cover their butts in terms of bandwidth supply. An unexpected influx of users means IPC capacity issues which leads to delays from Telkom and degradation of services. Whether or not this will change with fibre for those providers that don't need to use IPC, remains to be seen. I don't think the number of active fibre installations in SA is anywhere near critical mass, and already reports of performance degradation are making the rounds.
It may sound like a conspiracy theory, but there also seems to be a fair amount of "collusion" between the local ISPs where fibre is concerned. In the early days quite a few ISPs offered line-only options on Openserve for example. Now there are maybe 1 or 2, and even those don't list them on their sites, but will admit to offering the service if asked directly. Why? Because it's more profitable to sell you the line AND the data, and even though you're not locked into keeping them as an ISP, the prospect of spending weeks without internet due to the downright stupidity of the migration system is more than enough to put people off.
As for this thread, I don't really see consumers making sure of anything. Props to jacof for his endeavours, but all I saw was the pattern I described above. ISP underperforms, user tests various other ISPs to find one that performs better, moves there. There was no public outry, none of the ISPs that didn't perform have been brought to task or made public acknowledgements, and continue to offer the same level of service to hundreds or thousands of less savvy users who don't know the difference. And shaping / FUP still applies. Your IPTV experience may be amazing from whatever ISP the IPTV offering has partnered with, but the rest of your internet experience could be garbage.