There is no waiting at all to get onto the ship. At least we didn't.
We cruised on 11/22 of this year. Our check in time was 12-12:30pm. We were dropped off at luggage drop off at 12:15p, they took our bags and we got into a line that was marked with our time. (There were two other lines besides ours each 30 minutes apart, one before and one time after ours. The after ours line was not allowed into the building yet, so do not arrive early.)
Before we got into our line, someone checked to make sure we were in the correct time slot. They also told us to have a copy of our covid cards, negative tests and boarding pass available.
When we got to the end of that line, the checked all three things again, and were let into the building.
Went through security. No wait.
Our next line was to go to covid testing for my unvaccinated child. That took 45 minutes from time of check in/test to results. This is the only time we "waited" for anything.
Once we were cleared, we went to the computer check in - scanned passports, verified our photos, vaccine cards and test results, credit card on file, got our wristbands.
Last stop was actually checking into the ship - they scanned our boarding passes and we were onboard.
We had no waiting. The only chairs to be found anywhere (that I remember seeing) were in with the kids PCR testing site. And there really wasn't a line. The longest line was the first - maybe 4 families in front of us - for them to check and recheck our covid cards and test results.