It is said that never reuse an address, but the news is stating biggest bitcoin addresses are buying? It is said that we should never reuse addresses, so I think one time into the address, and one time out, and that address should be abandoned.
So the top holders of bitcoins should know that too, but the news is having headlines:

Top 100 richest Bitcoin addresses bought 17x more BTC than sold in last 30 days
Top 100 Bitcoin addresses accumulated $11B more BTC in the past 30 days

So why aren't they following this simple rule?
This is mostly about privacy

Because they don't care about their privacy

Because they don't care about their clients/customers/friends' privacy

Because they want to keep their code simple

Because they don't want to keep a database of their addresses

Because their identity is already obvious: This is the case for exchange wallets

Because multisig addresses whose transactions require mulitple private keys to be signed are one each and I'm not aware of a &quot;multisig hierarchical deterministic wallet&quot; system. Multisig addresses are intended for reuse, at least until someone finds a way to solve this