You probably take your internet and electricity costs as a measure of what you invest and get - but internet and electricity prices are quite low in some countries. If we believe the data I found on one page are correct, Syria has internet that costs about $6 a month, and the price is similar in Ukraine - while that price in Russia and Romania ranges between $7-10 for very fast internet. After all, it is not uncommon for multiple users to share the same Internet connection, just as it is not uncommon for the illegal use of electricity in some countries to be a way of life. What I can say from my experience that even today the majority of faucet users come from Russia, Ukraine - any faucet owner can tell you that.
https://www.cable.co.uk/broadband/pricing/worldwide-comparison/
Faucets were not generous in the sense that they paid more than today if we measure it in fiat, but when the price of BTC was around $200 the rewards ranged from a minimum of 1000 sats per claim to 10 000 sats per claim. There were no short links on faucets then, claims were quick and easy, and with the help of a rotator you could collect between 150 000 sats and 200 000 sats in less than an hour. With the help of referrals, the total amount could rise to close to 1 million sats a day, which again was only $2.
There is actually no difference between earnings then and today, except that it is much harder to make a claim because of the short links that have become a major source of income for faucet owners.