I think this is really interesting.

Stadia didn't require a subscription. You could just buy games and play them. But loads of people came to the conclusion that you needed a subscription. My going hypothesis is that this was caused by the free trial of the subscription service (higher resolution, cheaper games) that everybody got when they launched. So since people couldn't access the games without getting the free trial they assumed that this meant that they couldn't access the games without a subscription.