According to yCharts the size grew exponentially, but suddenly dropped from almost 1250GB to 500GB.
Why did the size dropped of suddenly within a day?
This behavior is important because having the chain size below a certain level makes it possible for hobbyists with a low budget setup to run a node.
If I'm not wrong, yCharts uses Etherscan as data input.
Anyway, it's because they enabled pruning for their computation, basically dropping old trie that are simply not necessary to hold on to as they are most probably not going to be subject to a reorg, freeing lots of space and still allowing to answer any request on the recent state of the blockchain.
It's in essence what EIP-4444 aim to standardize. State pruning was introduced in geth 1.10.0.
If you look at the archive node chart here, you will see that nothing changed for an archive sync, no data was lost.
