payment channels and the "lightning network" present solutions to the micro-transaction problem for bitcoin. They are worth looking into. However on bitcoin, they wouldn't be sufficient alone to scale up the network.
The problems of bitcoin go back to the 2017 block size wars. I think it is possible to scale the network up through a combination of measures (bigger blocks, payment channels, atomic swaps). But for better or worse, the current (BTC) developers have prioritized maintaining bitcoin's legacy and have split off from the other group of developers (BCH and others) specializing it into an efficient payment network. So BTC itself is a bad example of what cryptocurrency is capable of today, it has old network parameters that sort of gimp it. Those $1 fees you're seeing are not representative of the current state of technology.
You make a good point that bitcoin isn't really divisible enough, with the current prices. The floor of 0.1 cents is prohibitive for a lot of micro-transactions. It's not hard to imagine a world in which 1 satoshi is worth a couple dollars or something, which would pretty much eliminate the use case of micro-transactions altogether.