Firstly, 191 GB blocks aren't a possibility.
They aren't a necessity, but they are a possibility under your proposal. Why do you want to allow something unnecessary yet scary?
There's no way that many businesses/people are going to switch to Bitcoin in 30 years.
Why?
Secondly, 50% growth year over year is offset by a 17% decline in bandwidth and hard drive prices
No exponential growth can last forever. HDD capacity growth slowed down very significantly several years ago.
If we got 5% that'd be awesome, and that's 900mb blocks. 900mb blocks may sound terrifying
With second layer solutions like LN, even 900MB blocks aren't necessary to absorb all transactions of entire world population.