That’s stressful.
Being at the airport with 50 minutes to departure and not a single person checked in because of a system outage is not what you want to hear.
If it’s a full server issue, at least you’re not alone, but that doesn’t make it any calmer standing there watching the clock.
Hopefully they either delay the flight or start doing manual check in. Would be wild if they expected people to just miss it because their system is down.