The majority of the growth was at the sub 0.1 levels and it would be really poor UTXO hygiene to have multiple addresses at those distributions so I'd place my bets on those being individuals.

I don't sweep anything smaller than 2M sats to cold storage anymore and in doing some napkin math, I'm probably going to bump that even higher in 2024. I had already moved it from 1M to 2M in 2023 and if adoption continues to ramp, mempool continues to be full with fees ramping, it's going to be very costly for those that haven't been on top of their UTXO management.

Hell, I was in a Space yesterday with some Bitcoin veterans and even they didn't quite understand how UTXOs worked because wallets have obfuscated that away under the guise of end user UI/UX simplicity.