I also think the price caused the fees growing 10x or more because when people see that price grow either some of them start sell and sending bitcoins either they start buy and a lot of transaction are done on network.
It's called economical activity, which Bitcoin unfortunately still has problems dealing with. Eventually there is no way back anymore because the use will only increase further and the mempools will be clogged up even without the price causing it.
Segwit hasn't had much of an effect so far and it has been struggling to break that 50% support mark for quite a while now. Batching transactions is what took most of the pressure off the network, let's not forget that.
Segwit gave us a 15-20% block size increase on average, which is peanuts in the grand scheme of things. There is no point in acting like the fees are "just" $3-$4 so it's better than how the situation was in 2017. We're in 2019 now so let's look forward.