Need Cruise Line Advice Please

I'm making myself crazy going down multiple rabbit holes trying to find the best fit for myself and my husband and am hoping to find some help here. We would be first time cruisers but will be traveling with others that have cruised several times. We frequent Mexico resorts (both Cancun area and Cabo), have been to many Caribbean islands, just got home from an 11 day charter in the BVI's but next year my BIL and I are both turning 60 (and we are a "young" 60) and are thinking about a sibs Caribbean cruise for our combo bdays.

We'd be 6 (maybe more) in the group, are more day drinkers than night owls (although we do want entertainment options at night), love great food, all healthy/active, don't mind getting dressing up for dinner but don't want to feel "stuffy", want a good variety of activities on the ship (husband wants a casino), want a newer ship, looking for premium (or better) cruise line. We are more about the ship and less about the ports and definitely need an adults only area. I've been stuck on Celebrity, specifically their Royal Suite in their Retreat Suites and am now questioning if that's the best fit. I know one of you will pull through for me and push me off this cliff. TIA and Happy Mother's Day to all the moms out there!!