If you rent a car and it says "unlimited mileage. Speed reduced to 3 mph after the first 10 miles". The car keeps driving, it is "unlimited" but useless for normal usage.
Netflix and youtube will simply not work (buffering for 5 seconds every 3 seconds is not working), but you can keep using it for "whatever"* (*maybe, sometimes, for the first 10 days).
DVD quality is hardly 3 MPH. DVD quality is more like unlimited miles you can only do the speed limit.
Using a phone with "only" DVD quality streaming video is still perfectly usable. Sure it's not HD quality, but if you are streaming over 22TB a month a small decrease and video quality isn't a big deal. How much are you going to see on a small phone screen anyways?
On the Fi Flexible plan, video streams at the highest available quality. On the Fi Unlimited plan, video may be streamed at 480p (DVD quality).
It doesn't say anything about less than DVD. So assuming good signal strength/infrastructure you'll likely get better than DVD for 22GB then "only" DVD after.
- On the Flexible plan, while under your data limit, video streams are at the highest available quality.
- On the Unlimited plan, while under your data limit, video streams are at DVD quality, even if you have a very good signal.
The throttling is in addition to that:
> If you use more than 15 GB of data in a cycle on the Fi Flexible plan or more than 22 GB in a cycle on the Fi Unlimited plan (less than 1% of individual Fi users as of Jan. 2018), you'll experience slower speeds (256 kbps) above those respective data thresholds until your next billing cycle begins.
What you are proposing would be completely fine (throttling to DVD speed), what they are actually doing is "throttling so even just reading websites or google searches becomes annoying".
If you rent a car and it says "unlimited mileage. Speed reduced to 3 mph after the first 10 miles". The car keeps driving, it is "unlimited" but useless for normal usage. Netflix and youtube will simply not work (buffering for 5 seconds every 3 seconds is not working), but you can keep using it for "whatever"* (*maybe, sometimes, for the first 10 days).