A few years back before maybe the 2017 FOMO rally there were many people that actually did do faucet farming, however they didn't need cellphones for that they just needed a desktop.
True, some people even did it with one phone as there was a way to duplicate browsers on their phone. If I remember it correctly there were many people shared screenshot of their phone with so many duplicated browsers (UC browser). 1 browser for 1 account, 1 account is being used as the main account and the other accounts are referrals for the main accounts. So they were abusing the faucet and the referral program at the same time but I believe they were banned eventually.
I remember PrimeDice a few years back had a large faucet, it was like 2000 Sats and if you wagered alot of BTC then you moved up a few levels and maybe got a 3000 or 4000 Sat faucet. There was a small time-delay and captcha but it was pretty easy to turn that 2000 Sats into the min withdraw.
Also the existence of the pvp game at Primedice, the game helped abusers to collect the claimed faucet into one account.
Obviously people started to abuse this method in 2017 and they had to lower the faucets and eventually remove it since it became too much work to keep having to deny withdraws from people who never made a single deposit.
I still wondering why many people abuse faucets? Indeed it can make them earn some amount of money, but dont they have other works/activity in real life so they have many times to abuse faucets?
I think it have to work because someone have make millions with spotify like that
A mobile phone cost here like 30 Dollar with Android
10 x 30 =300 Dollar
For charging its nothing muxh to pay
That means i can make with 10 Phones 24/7 something to earn btv but i dont find the right way
Even if there is a way for you to do it, it is obviously against the terms of the site you are going to use (freebitcoin). Sooner or later, freebitcoin will catch you and ban all your accounts. Once it is happened, you are wasting your invested money to buy the phones.