I did some back of the envelope math and it's hard to justify the cost.
They say 25 MPS download is enough but people weren't getting decent results without extremely good internet on project stream from what I've read.
So without knowing more I'll assume you need the best internet available for comparable results to a console or PC with the game installed.
My current internet plan is 50 Down/10 UP 300 GB CAP per month which runs $60 after tax.
In my area 1 GB down 50MB UP uncapped data plan runs $120.67 CAD after tax per month.
So it's $80.67 P/M more expensive than my current plan or approx. $970 per year more.
That's without the potential subscription cost of the service. So it's be generous and say Stadia will be $15 CAD/Month or $180 per year after tax.
So using Google Stadia would cost me $1150 per year.
$1150 is enough to buy an Xbox One X, 12 Months of Gamepass, 12 Months of Gold and a cheap 4k TV.
Mind you this is the first year cost equivalency.... which drops precipitously in year 2 when hardware is no longer needed to be purchased.
Plus you could always recoup some of the money by jettisoning the Xbox One X and 4K tv if you needed to.
I'm in a large city as well and not like i'm out in the boonies. Who is this service for?