Definitely worth it here. We got one when DC was 1 and could work out the basics of change characters for different sounds and stories really early. DC is 3 now and they’ve got the hang of it properly. Every Christmas and birthday I will ask for tonies for them, they’re quite expensive at roughly £15 per tonie but grandparents seem to like buying them (once you demonstrate what it does otherwise they think it’s £15 for a bit of plastic). The tonies hold their resale value really well, usually reselling for £10-11 so as your DC grows out of them you can sell the old tonies on and buy new ones. You can also buy tonies second hand and resell for the same price assuming they’re kept in a good condition, so you’d only be losing out on postage.
There will be someone saying it can’t replace reading but we don’t use it to replace reading. We use it every night after we’ve read for lullabies as they go to sleep, for bath time, cooking/baking in the kitchen, when we need screen free time, in the car, when we’re playing and want a story or music in the background. DC likes the Paw Patrol ones, Paddington, bear hunt and gruffalo ones. I’ve put a few more like Room on the Broom and Zog on their Christmas list. They also really like the songs ones so there’s a little dog one with a ball and a pig with a drum that they like listening to and singing along with.