Disclaimer: this is just my own opinion and observation I wish I could not offend someone.
I think all Freemining sites are scam, they will will pay first to make people trust them. And ofcourse someone will invest because that site is known as paying.
At first they will pay you, but you don't know when they got millions thousand of user and got big investment they will vanished like wind or shadow.😂
I think if you want to invest on free mining site like offline mining site it's good to invest when they are new.
My first Investment on offline mining site is on Faucetbch you can mine Bitcoincash. I invest 4.50$ and last week they got 40,000 users and now they got 200,000 users , I already witdraw 5times I just give it a try.I think this site will also vanished soon.
So what do you think? Do you trust offline mining sites ?