The dummy has been so useful for both my boys. You know what's best for your child. My baby was sucking his thumb and I personally prefer him having a dummy over his thumb. There's absolutely nothing wrong with giving a dummy especially if it helps them sleep. Eventually you'll wean them off anyway.
Don’t let anyone make you feel guilty for the way you care for your baby ❤️ whether that’s how you feed them or any other choices that work for you and your baby. We used a dummy for my son til he was 1 but my little girl refuses to take one. We’d rather she had a dummy than sucked her thumb as you can take a dummy away but not a thumb!
My MIL was exactly the same when we first gave our baby a dummy, but she now sees how it’s just there to soothe and not something she has in her mouth 24/7, so she’s definitely come around to it. I completely agree with @Amy too, you can’t take away a thumb so a dummy is a good alternative!
I think the reason the older generation don’t like dummies is because they don’t understand updated advice. Dummies are now made in an orthodontic approved shape so aren’t “bad” for their mouths/ teeth and dummy use has been linked to reducing the chance of SIDs! Definitely don’t feel guilty for trying to comfort your baby with one if it’s helping and the alternative is that they are upset.