When we talk of bitcoin supply, we look at it as 21 million bitcoin, and people wonder how that can serve the whole 7 billion population, but we forgot that there are smaller units of bitcoin, we have the mbtc, we have the ubtc and we have the satoshi, and i will like to talk on the satoshi which i believe needs to be expanded to really serve the current economy
These and similar thoughts had been mainstream here like 4-5 years ago
When people really believed that Bitcoin can substitute fiat currencies one day (and that day was not too far in the future) and seriously expressed concerns that Bitcoin's denomination won't suffice and thus should be expanded to, say, 16 figures after the decimal point (instead of outright increasing the total supply)
Now such ideas seem completely out of place (and time) as Bitcoin is not serving the world even in its present state. Sorry if this is not what you wanted to hear but it is better to see what is really going on, however unpleasant it might be. Other than that, what you suggest is what altcoins already do, effectively expanding Bitcoin's supply