I worked for a company, where I really did have nearly 100% uptime at my local data center in our office. I wasn't a luddite, and the cloud wasn't something I was afraid of or didn't understand. I just, at the time, had an infrastructure in place before the cloud existed, and it worked well enough at a great price point. We were on the same electrical grid as a hospital, our infrastructure handled our scale, and just really didn't have problems for a long span of time.
Still, someone came in and said.. what, you are still doing stuff on-prem and not the cloud!? How legacy! How dated! And so the push to the cloud came next.
We migrated to the cloud (and some colo facilities for some equipment we chose to keep), and on the 3rd day of being freshly migrated, the cloud provider had a major outage and went down for longer than we'd ever had on prem. The next month, the colo went down and their diesel generators failed, and it was down for an entire afternoon.
Oh sure, there was some SLA money returned in that event from the colo...
I'm just saying, I've been on both sides. Tell them the truth - even the cloud has outages, but it is certainly more "convenient" to have hundreds of engineers work on fixing an outage at global scale, and all you have to do is wait for it to start working again - then it is to have to fix it all yourself.