I’ve been on flights where an announcement was made at the start of flight that the internet didn’t work — only to find that it worked just fine. That worked out great, not only was there internet but no one else was trying to use it so I had plenty of bandwidth.
I’ve also been on plenty of flights where internet doesn’t work and the crew was aware of this from the prior flight but didn’t say anything until we were up in the air. That’s frustrating because I’d have treated the half hour I was on the plane (on the ground, still with connectivity) differently.