Drinks packages are always an add on. It will depend on what you drink. It needs to be worth it.
We last sailed Royal Caribbean. For us, it wasn’t just alcohol. The drinks package included bottled water (which we both drink a lot of), coffee from the coffee shop, freshly squeezed OJ at breakfast as well as alcohol.
I am going from memory but I think the drinks package was around £40 or £45 each a day. Bottled water was £3.50 a bottle. We would have 5/6 bottles a day. Fresh OJ was £5 a glass. One each day at breakfast. I think the coffee shop was around £3 or £3.50 for a coffee and we’d probably have 2 or 3 a day. I am sure that lot was around half the cost of the package a day. We’d have a glass of wine or a beer with lunch then a cocktail at the pool, then a wine with dinner and a liqueur. It certainly all added up for us so it was worth it. Everyone is different though.
You do get coffee for free on Royal Caribbean but it’s mass produced in big urns. Not my kind of thing and they do offer juice at breakfast but again not my thing. Cruise critic forums will give you a good indication on individual costs and working out if it’s worth it.
Spending wise, your cruise should include all food and most entertainment. They may offer extras such as cooking/baking/sushi making at a cost but you can decline. If you don’t do a drinks package that is extra.
Spending wise, it’s what you want to do on shore such as trips either organised by the cruise line or on your own. We prefer on your own. May be morning tea or lunch in port, ice cream or a tour with an independent tour guide. Factor in a taxi if you go yourself or the bus. A bit of shopping.