Why are my parents persistent about kids & relationships?

Once in awhile they will make comments to me. One time, during breakfast, they asked why im not dating anyone yet. I told them I don’t want a relationship after my ex. My stepmom proceeded to tell me “but you are 24! I got married and had my child at 21” and i said “ok but thats YOU. I have my whole life ahead of me” and she said “you are gonna be 30 in 5 years. What about kids?” And i said “I don’t want kids and I can meet someone in my late 20s or when im 30 when im ready”. Then, another time, I was at the store with my dad looking at the cute valentines day things to treat MYSELF and he began telling me I should begin seeing people. Then just last night, I was stressed about money and my dad told me “you don’t have to pay 10k a month for a house just wait until you have to!” Then my stepmom told me “oh and wait until you have kids! And you have to pay $400 for childcare!” And I proceeded to say “nope. I won’t need to worry about that because I won’t be having kids. Just pets!” And my dad made the ignorant comment to say “pets are more expensive!” And i said “no they are not.. they also don’t take away your freedom or privacy. I can leave my house whenever I want with pets. I can work a fulltime job with pets. They don’t throw tantrums in public or cuss you out because you didn’t buy them what they want” then my dad changed the subject.
Why are my parents persistent about kids & relationships?
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