Initially, when PI Network created a lot of hype, I was skeptical about it. Because where people are investing huge amount of money to build mining rig, how can it be so profitable for its miners only through mobile mining? However in the beginning I also mined with its hype but after a few days it didn't seem very safe to me and so its stay on my phone didn't last long. Anyway, I think it will eventually come out as a scam, so I will tell everyone not to invest in it, also don't let it place on your mobile.
You don't need mining rig to mine Pi Network, I think you are speaking of another thing. You only need a mobile phone to mine it.
I have always have concern about the project, a lot of tokens has been mined already and they seems to be promising people significant riches just by holding the tokens, with all these Stanford people that are being used to front the project if you looked deeper something seems wrong, I have said it before that Pi network is being used to mine users data, I have not seen anything that the project stands for they even add ads to the apps this is the first red flag for me, if you think you want to make people rich why turn your users to your product