I certainly agree that giving very young children unsupervised access to an internet connected device is probably a bad idea. However I question your classification of it being "addictive" and of that being the worst part.
Imo playing around on a tablet is only addictive in the same way that reading a good book or playing a good video game is "addictive" - i.e. you're having fun, and you want to keep doing it because it's fun.
Of course there's specific apps you can download that are fine tuned to actually be "addictive" through randomization and monetization strategies. But claiming that the whole device is bad because some bad things exist on it seems wrong to me. There's thousands of hours of beneficial, educational, non exploitative fun to be had with a tablet/laptop/phone.
I'd be much more concerned about my kids talking to dodgy people in chat apps, or using my credit card without realizing (or with realizing), or accessing porn or something.
