Each order of magnitude of network speed increase matters less than the one before it as more stuff is trivial, and there's less stuff that is still problematic. There are things out there for which gig is a noticeable improvement over 100mbit, but not many. As time goes on and things grow it'll matter a little more, but still not a huge amount.
Eventually we may find that something is "enough" for end users and further upgrades aren't needed, perhaps in the 10gibt range. That even when we are doing all kinds of things with it, it ends up being fast enough, and not having any real benefit to go higher.
Right now, 20mbits or so is "enough" for most users. If you get multiple users in a household, or like to download large games or something, more can be needed. However even for that, 100mbit ends up being "enough". Moving to something higher isn't real noticeable. Steaming works no better, webpages are already fast, all you get are a bit less time on large DLs but you didn't spend much time anyhow so no big deal.
It's fun for sure, and I'll probably go to gig when it comes to my area (I have 150mbps now) but only because I'm a geek who likes shiny toys. When I stepped up from 30mbps to 150mbps I noticed no difference at all except for Steam downloads, it is a luxury, not anything that really matters.