Babies use bottles for feeding from birth until around 6 to 8 months of age.
However some babies will continue to use a bottle until age 1 to 2 years old which is okay and normal.
My younger brother used a baby bottle to drink his milk from until he was 10 years old and he would not drink his milk from anything else.
So our mom allowed him to use the baby bottle to drink his milk from until he wanted to give it up.
He drank other drinks in a sippy cup when he was 1 year old and would drink from a cup when he was 3 years old as long as it was not milk.
For some reason he would not drink milk unless it was from a baby bottle.
There's nothing wrong with that though and it's better to get the milk down than worrying about how it's drank.
I gave up the baby bottle by 3 years old fully but my younger brother would not give them up until 10 years old.
My younger brother was also on the pacifier until 10 years old.
He would also not potty train until after his 9th birthday so my younger brother was in diapers full time from birth until almost 10 years old.