I think it's an issue of being good enough for the types of things we do now. If it got astronomically better, it would enable things that we flat out can't even consider doing nowadays.
"If you build it, they will come" isn't a good reason for such a large investment.
I think it makes more sense to focus on universal access to 50mbit for every household. Someone going from 600kb/sec DSL or Satellite to 50Mbit is a huge benefit. Going from 50Mbit to 1000mbit have very marginal benefits for a single family home.
https://support.google.com/youtube/answer/1722171?hl=en
For pre-encoded HDR 1080p Google (youtube) recommends 15Mbps target rate for the video and 0.5Mbps for the audio (5.1). For 4K the numbers go up to as high as 85 and 0.5.
I use a rough rule of thumb that 'livestramed' things at the same quality should be double those bit-rates as a maximum.
This gives:
FHD 16Mb/s
4K 86Mb/s
86 * 12 ~= 1032 Mb/s ; Thus Gigabit is NOT overkill. It is capacity and freedom for a small family and some guests to enjoy content and/or collaboration without anyone 'hogging' the connection.
Nobody is going extra for gigabit just to throw crazy 4k LAN parties.
How about someone else installing a game they just got or want to re-install to play with friends?
Like I said, it's about having the capacity to handle the WORST case that could get thrown at it without impacting other users in the house.
It may not be what the majority to, but it's a non trivial part of the population.
We're a "cord cutter" household with three adults and a four year-old who has her own iPad. I wouldn't be surprised if we were top 1% for bandwidth users. Tops for us is probably one 4K stream (25 mbps), 2 HD stream (5 mbps), and then trivial amounts on top of that from the three adults intermittently playing on their phones. I've got 150/150 now, and will be upgrading to 750/750 when Verizon rolls it out in Annapolis. But really only because I can, not because I can use it.
And improvements are coming, 4k 60fps HDR streams will come sooner rather than later, and they consume upwards of 100mbit pr stream.
Okay, get me started, what is something? If they possibilities are endless, there must be a concrete example, right?
When I had a 56.6k modem, I was trying things way beyond it's capabilities as far as sending and receiving large files, playing games online, it was a disaster and there was very obvious and very real problems to be solved. And much more came after that, streaming movies!? Who knew.
With fiber, nothing seems to be coming close to pushing that limit from a consumer perspective. If there was something that was kinda shitty but still works okay on cable, what is it? Or what thing just isn't possible that is waiting for a faster connection?
I have a 25mbps connection, slow cable, and it does everything I need pretty flawlessly. Does it have to buffer sometimes for HD movies? Sure, not worth $50 more a month for that. I don't know what I'm missing out on with my slower connection, and if I am, people are doing a horrible job marketing what that is.
Once they get things set up for their cameras, they realise that they can suddenly reliably watch 4K netflix; some have started streaming to twitch/youtube because it costs them nothing, and heaps more.
On the other side of the argument, there is the 'privacy' aspect of things: most people would never run a home server that runs email/social/backup for you (and connect to it from your phone while out and about). However once fast home internet connections are ubiquitous, I fully expect people to start taking back their data from google/facebook/etc of the world
Faster internet is like wider roads: the mere presence of it increases demand.