If I destroy 1 XRP for fun as transaction cost, this would have been enough to pay for 100k transactions while costing me about 3 US cents and it would leave quite a spike on that chart.
You can only do that for so long before you run out.
For about 2 decades, yes - and I could do it completely for free, as I got my XRP in giveaways.
Edit:
The main point is that users paying high fees is a poor measure of performance - cash transactions have 0 explicit fees but amount to huge sums compared to BTC or Ripple.
I am for example quite sure that VirWoX with their large markups makes more money in fees than some far larger/higher volume BTC exchanges. Would you consider them "larger" because of that? Ideally there are 0 fees and the closer you get to this ideal, the harder it gets to be considered "large" by you.