They don't replace humans.
I have 2 dogs at home. I love them A LOT, am paying a lot of money to keep them safe, well fed and healthy (they're both 14-15 year old, so we're expecting the ... unexpected). They love us and we love them as is they were some sort of furry kids for us. They are members of our family in a way, they have privileges and we do communicate, even if non-verbally from their part.
We do not dress them, we don't celebrate their birthdays, since both were rescued from the streets, so we have no clue about their birth dates. When they'll pass away (which will be a VERY hard time for us), we'll make arrangements to bury them somewhere nice.
We have never used them as 'human replacement', we get along with people well, have friends we love and like meeting new people. The love we share with our pets is indeed special, but it's not 'human' ;)