The large backlog these days is mostly spam transactions with almost no fees. Bitcoin has increased capacity dramatically in the past decade.
Fee rate: 51 satoshis/vbyte
SegWit transaction with 1 input, 2 outputs: ~172 vbytes
In total: ~8772 satoshis == ~4.48 USD
Make note of the inflection point around 2016. Yeah, it's right around the time your capacity chart starts looking like a wet noodle.
Yeah, that's when a few your scumbag BTC devs removed Gavin Andresen's commit access and killed BTC's last chance of becomming a real currency.