Not sure why you're so confident in Google, they don't have the track record. At best you'll maybe get a year notice. If it doesn't actively generate money there is little incentive for them keep things around
from a android user's perspective i used to use google keep all the time before i got privacy concerned and I still see a whole lot of people from my friends and family using google keep. I can assume it's true for a large quantity. I don't think a company like google would stop this type of service where they can get a large amount of personal data users just leave opened.
