While it is true that the 2017 bubble was the largest in Bitcoins history,
was it really the biggest bubble?
note that being a big bubble is not about being in the highest price but having actual big BUBBLE. I personally consider $10k to $20k a bubble which means it really wasn't that big. in fact it can be considered one of the smallest bubbles. even if you consider current price as the bottom and take the 80% drop as the bubble burst (which it really isn't true) that still doesn't make it the "biggest" because we have had bigger bubbles in the past.
the market capitalisation of both Bitcoin and the cryptoasset ecosystem still exceeds its January 2017 levels -
I am sure this will happen for bitcoin but it will not happen for at least 80% of the altcoins and the rest of 20% will have an extremely hard time to reach their previous ATH because most of them have already lost their place in the market and are being replaced by newer altcoins.
In terms of marketcap decrease it's by far the largest but I agree that shouldn't be the only measure of what constitute's the biggest bubble. I think one of the most important things is not something that even can be quantified, but the effect the bubble had on the market. With hindsight you may be able to measure this based on how long there is from bubble burst to a new ATH but I'm not even sure that is fully accurate. To my mind 2014 was a bigger bubble due to the shear influence it had on the market.
You're doing the current market an injustice saying it only exceeds January 2017 levels. The marketcap at the turn of 2017 was under 20bn, bitcoin being the only coin with a marketcap over 1bn. The overall market has still grown massively since then.