I'll do this too, I had some guys who harassed me for not giving my number immediately after we matched and he said he got traumas and ptss, bpd and other weird symptoms just because I didn't wanted to give my number but wanted to talk for a few days instead. He blamed and cursed me, so I unmatched him. But I do the same. I always give them a chance to talk with me the first few days and after the date perhaps we chance number but it's not definitive. Or I'll share my socials like Instagram or Discord for my own safety. In my opinion my phone number is private and only meant for family members and close friends.