In a household with 5 people, that is 25/10, which does fit into the FCC's definition.
WISPs are popping up left and right that can do 1000/1000 per access point, which can be shared with all customers within about a 500ft radius. That's definitely doable with the above definiton of broadband. Basically, it's one wifi-based access point that has a uplink, and each household has an externally mounted wifi antenna that then redistributes to a conventional home router.
On the other hand, I personally have a WISP in a dense urban area. I pay $45~/mo for guaranteed 100/100 - usually, my sustained speeds are closer to 200/200, or 300/300. It's an antenna on our building that is the backhaul for about 50 households.
WISPs are viable in rural areas - they bring broadband to those who can't get it.
WISPs are viable in urban areas - regions where installing new copper or fiber would be prohibitively expensive, they allow upstarts to challenge the duopoly.
Just about the only awkward middle ground where the economics get a little tough is in spread suburban areas.
maybe! I video conferenced on 1.5up for a week and I did have to turn down send quality, but other than that, it was fine.
I think the bigger issue is that if you can only get 1.5 in 2020, then that means that the physical layer between you and the internet is tenuous. Like, DSL far away from the DSLAM and thus packet loss and line noise.
For the heavy uploads I usually resorted to doing the upload from a VPS instead though, when possible (build the artifacts from that VPS, so that both the build and upload are much faster).
There are also a lot of crappy WISPs out there, so this is by no means definitive. Same as there's lots of crappy frontier copper wireline 5Mbps ADSL2+ still out there on degraded copper lines from 40 years ago.
$99 for 15/3 mbps, or $139 if you want broadband: https://ethericnetworks.com/residential-service-plans/
$50 for 2.5/2.5 mbps, or $679 if you want broadband: https://ridgewireless.net/ridge-wireless-plans/
And yes I do know people who have had problems in these counties. I also had an absolutely miserable experience using Charter due to their poor infrastructure in the valley. Internet on nights, weekends, holidays, etc. was unusable due to their high utilization of low bandwidth lines