I know that Venmo and Paypal are the most popular payment applications in the US but are they more or less secure than some blockchain based payment applications like PayCircle? Would love to hear some opinions on this.

Thanks for the info, will do.

I recently came across a new currency https://diamcircle.io/tokenomics which though initially based on their own proprietary tech have transitioned to ERC-20 in the span of a few months. Would the coins I have already mined be changed on their own ? or would the older protocol still apply to them?

Thanks for this list. I came across another one that might be launching in 2022. It is based on the Erc-20 protocol: https://diamcircle.io/tokenomics