There is always two things when bitcoin is moved from dormant addresses, it is either to change wallet due to security concerns like maybe the back ups for the wallet might be missing; probably one of the multiple back up they have goes missing and for security purposes they change wallet.
It can be fund reallocation from old wallet to new ones. It can be change from wallet softwares and brands that make that person thinking like changing a wallet software and moving the fund to a new wallet is necessary. It can be issue with wallet backups so that with still accessible wallet, that person decides to move it to a new wallet with backups for recovery.
Another reason that is related more to technical concern like changing wallets from Legacy to Native Segwit for better transaction fees in the future. With Segwit addresses, it is more feasible to move bitcoins on chain with less expensive transaction fees than with Legacy addresses.
Another reason which I think should be why this address went life will be to take profit.
Surely taking profit can be another reason but it must be moved to a centralized exchanges in most cases.