Am I wrong ?

Why is it when u meet someone on a dating app or whatever, guys end up asking for social media besides phone number or anything? Is it just mee or does this happen to anyone else ? Is a red flag or am I just being weird about it

UPDATE! We ended up stop talking because turns out he was talking to other girls while talking to me. When I confronted him he would ignore the question and ended up talking about s*exual stuff so I ended it with him