I think in the early times signature campaigns were still less or not well known and I think faucet sites were more popular than them. It can be because we were receiving a generous amount of coins, as their value was still low. It is like it was giving us an illusion.
The first bitcoin I received was also through a faucet, it can be said that this was the easiest way to earn bitcoin in the early years when bitcoin was not popular, and is the only way I know to get it without investing the money.
Another good thing about the faucet before, is that payments on them are made straight to our desired crypto wallets. It was only sad that things have changed through the years and many faucet sites have now closed down. Signature campaigns on the other hand, are now the ones which are booming. I guess this is because cryptos are now popular, so a lot of start-up projects in this field are also opening up and they see a potential in signature campaigns to promote their brands.
At each stage of development we need different strategies, you cannot ask the faucet to continue to exist while the price of bitcoin has increased millions of times and is worth more than $60k. If it were you, would you be willing to use your bitcoins to distribute them to everyone for free? So the faucet's disappearance is understandable.
Bitcoin has become very valuable and those who want to own it today need money, which will further increase the value of bitcoin. If it is still given away for free, I believe bitcoin will not be able to achieve high value.