thanks for all the answers!

it really shed light into some deeper issues I hand't think about

Thinking more carefully, $1 for satoshi is a very high price even in the long term.
As a bullish bitcoiner, I guess we may reach $0.1 for satoshi considering the purchashing power of the dollar today. I say "considering the purchasing power of the dollar today" because all fiat currencies tend to severe devaluation in the long run, which means that $100 in 100 years could be worth less than $5 today.

Anyway, I don't think there would be a need for bitcoin to be more divisible in the next decades.
Moreover, it would be a complete mess to try to make bitcoin more divisible because the software would have to handle past transactions and future transactions differently, introducing a lot of complexity.

Thank you all for the answers. It clarified my doubes