I have noticed some parents doing the baby-talk to their toddlers as if that is the right and proper way of talking. Parents should know that toddlers are observing the way the adults talk because they mimic us. If we do baby talk then they will learn baby talk. Isn't it logical?
Toddlers aren't fully mature yet, and the parents just do that to them because they want to stoop down to their level because it's amuses the kid and makes them "fit in".
One neighbor has a 4-year old boy who couldn't speak properly because of the baby talk of the parents and the older siblings. I wonder why they need to use baby talk when it is easier to talk in the right way. It is an easier way,
Talking to kids in a babyish language early on is okay but once the baby is of 7-8 months and starts really listening and developing his own words and phrases, then it is important that parents use clear and proper speech so that they learn to talk well and pronounce words correctly.
If you search online, you will find a lot of techniques on how to stimulate speech from your toddlers. There is this speech therapist in particular who calls these techniques, “Communicative Temptations.”