Lots of the issues Bitcoin faces are not based on the design, but by and large what tech bros made out of it.

If you really want to learn more about it, have a look at the blocksize wars and Bitcoin Cash. Or just wait until Bitcoin finally collapses, which will happen eventually, but I'm not able to tell whether this year, decade or century.

What will break Bitcoin's neck eventually is the OPEX of its mining. Mining on the one hand is a crucial part of keeping the network secure, but on the other hand is expensive way beyond the money that can be earned from transaction fees collected when doing the mining.
Bitcoins being generated from thin air when a new block is being produced are a major part of the revenue for the miners, but the amount of BTC getting created this way gets reduced over time until it reaches 0.
The thing about the mining is that it's being done with more and more computing power, and it can't go below whatever the current amount of computing power is by a lot without putting the network at risk.