In article ,
newshound wrote:

7.5 trillion photos in one year is over 20 billion photos taken per day.

they estimate 8.8 billion photos in 2018, or 24 billion per day.

Thanks for that. I'm not too unhappy to be only out by a factor of 20.

Particularly as the "upload to google photos" will almost all be from
people who have ticked the box, which is something I am very reluctant
to do. I've probably got a terabyte or so on my NAS and other external
drives, and I don't at the moment fancy paying the current commercial
rates for that (obviously it is going to come down).

there is no monetary cost for google photos.

one thing online services offer that nases normally do not is being
able to access any photo from anywhere. you don't need to also have
copies on your phone and laptop. another is offsite backup.

it's possible to set up outside access to one's own nas, but making
sure it's secure is non-trivial, plus most apps aren't designed to link
to it anyway.