Why do people do this? Just curious! (Riyadh)

Hi everyone :-)

So here I am again sharing my personal experience here on Internations and asking the question "why do people do this?"

I generally receive a significant number of "contact requests" which I accept gladly as its always a good thing to connect with people that share similar interests with me!

However Ive found that I receive messages that will read "WhatsApp me, here is my number" or "send me your number we can chat on WatsApp". And I often ignore these type of private messages (and the sender) just to avoid sending a rude response.

I'm just curious to find out why cant we communicate via this platforms private messages or even forums? Why do we need to take it to our cell phones? Is this just an easy way to get hold of someone's cell number?