What is the cost for a multiple device internet package? It could be cheaper than the Key 18.99 price. For example, my family of 4 with a 4 device surf & stream package was $22.99 per day, compared to the Key for $27.99 per person per day. I got a great deal on the internet package, buying it when RCL was desperate for cash during COVID. It is now $63.97 for the same package. You get one internet code that can be used on up to 4 devices at the same time. If you don't all want constant connectivity, you might be able to share the code for multiple people. My children ended up streaming to their phones all the shows they wanted to watch (because the options on the TV were never great). If you get the Key, they give you a separate code for each person and it is only good for one device at a time.
My family has used the Key twice on previous cruises when the cost was about the same price you are seeing. It was really nice to have a quiet sit-down lunch, a place to drop our bags, and for the reserved shows on the Oasis class ships. We also liked the quiet breakfast the last day when we weren't in a hurry to get home. You also get a fruit basket and key chocolates delivered to your room. My kids never had issues with access to the other activities they wanted to do, so we didn't use the reserved times. We also didn't need the priority disembarkation at ports and I'll be surprised to see how that works with the new enforcement I'm hearing about for getting on the ship.
