$100/mo for absolutely unlimited is still an incredible bargain. $20/mo is in the neighborhood of almost free.
The average person could buy a $100 external drive and replace it every five years, and that would be enough.
$240 annual x 75 years = $18000
Almost free huh?
$12000 a year x 75 = $90000
If I could pay that in and lock it in for the duration, maybe I'd consider that, but no one is going to let you do that.
Y'all got some funny notions on "Free".
Then there's the whole issue of "What if Google gets bored?"