This is a project still under development, but it seems legit. If you dig a bit deeper and run a background check on the core team you will find out that those Stanford PhDs have a lot to put on stake starting with their reputation.

Reading the white paper on the official site and their FAQ section could clarify a lot of things about the progress of the project and why at the current state they do not publicly list any figures. As for the token supply on the white paper you will find the answer on the Pi Economic Model section. A lot of people thought of it as a scam at first but reconsidered as soon as they have done a proper homework, reading the material on the official site rather than rushing on false conclusions through unevidenced speculations.

I don't believe that its a Ponzi scheme as they don't ask you to invest any money into it. They offer you Pi on a daily basis as an incentive for being an active member of the community and increased rewards for promoting it further. Yes they do require some basic info from you to start with but these are info we already share on various sites and web apps during our registration.

Pi is expected to be listed to the crypto exchanges by April 2021 , so pretty soon I would say we will all get our answers. For those who believe in the project and join early there are certain benefits as with any other opportunity one chooses to be involved at an early stage.