I'm curious about some publications mentioning that "only 2% of the addresses holds 1 Bitcoin or more".
I found this to be quite surprising, since I always supposed longtime hodlers to be the larger segment of the Bitcoin ecosystem and not just a small fraction.
How accurate this data could be?
I do think that such data is accurate.
Remember that the insurgency on the price of bitcoin happened only on the years 2020-2021, in which most people are just staring to join the hype train. Some users who were able to receive bitcoin as early as on its initial stage are the ones whose wallets have more than 1 btc. I do think that such data is accurate and it shows that earning btc can be a relatively difficult task to obtain.
There are about 28 million non-zero Bitcoin addresses. Do you think 560k people holding 1BTC or more is a small number?
This is also true.
While 2% may seem 'low' facially, but the fact that there are millions of addresses globally make 2% a pretty huge number of people who own 1+ btc inside their respective wallets.