Zelle
Venmo doesn't have the option to send as payment for goods/services like Paypal does so you don't have that type of payment protection should something go wrong. Venmo has the additional social media aspect, but I have everything on private and don't care about that part. Some people care though I guess.
I stick to Paypal for online payments when buying stuff from strangers but I'm ok with Venmo for face to face transactions. I use both when it come to people I personally know depending on what the other person prefers to use. Most people use Venmo though so that's usually what I use.
If I'm buying things online from an individual, I'll only send money via PayPal Goods & Services, as there are buyer protections.
If I'm receiving money for selling something, I'll take it via PayPal or Venmo, as there's less risk and fees for me.
Venmo is something I'll use for friends, family for small things like meals or the like.
PayPal if for business
Venmo or Zelle if personal, which ever my friends prefer.
I like to keep my business accounts and personal accounts very separate.
it has to do with value, volume, transfer time, and taxes