Tbh with kids that age you can’t really go wrong anywhere - the exact holiday and where it is should be more planned with the adults in mind and what they would find fun. If parents are finding it fun, their children should too. My kids are a little older now, but not much. Between the ages your kids are and now, we’ve had trips to places including the following:
France, Dordogne region. Swimming and fishing in lakes, kayaking on the rivers, real caveman caves, castles with trebuchets and catapults, gardens with treehouses and mazes, tree climbing (like Go Ape.)
Mexico, Yucatan. Snorkelling, boat rides to see turtles and dolphins, zipwires, more caves, jungles, white beaches.
Turkey, Turquoise Coast. Living on a boat for a week, more snorkelling, hiking up waterfalls, kayaking, more white beaches.
St Lucia. Living on a chocolate plantation and making chocolate from scratch, more beaches, more snorkelling, jungle trekking, more waterfalls.
Skiing - can never get enough skiing! With husky sled rides, reindeer adventures, zipwiring, alpine roller coasters, ice skating, moonlit tobogganing, stays in igloos.
Been to lots of other places, but these are the stand out holidays in my kids’ heads. I offered them Florida the other year and they turned it down in favour of more jungle, snorkelling and waterfalls, but I am sure we will get there one day and they will love it too! If theme parks really float your boat, I’d say go for Florida, but don’t underestimate the ability of children to see the wonder in absolutely everything, and don’t underestimate the joy family time can bring them. We get our kids new playing cards every year for Christmas these days because they love nothing more than sitting in a tropical beachfront bar/mountain hut/skyscraper restaurant/hotel lobby playing cards with us and having a drink or ice cream sundae.
I can’t wait to be able to go on holiday with mine again!