Only individuals have interests. A group’s interest is an abstraction, built by aggregating the interests of its members.
An individual and their interests are both abstractions too. I know my own interests don’t always align and need to be aggregated somehow when deciding what to spend time and resources on.
One laptop per account. You’d never reuse a password, so why reuse hardware? When a device gets rooted, the attacker gets exactly one account. Buy from different manufacturers so a single firmware bug can’t hit every laptop. Each account also gets its own email address (on its own laptop), backed up with recovery codes stamped into steel plates, one set stashed in your shielded office and one in a safe deposit box.
Burn a fresh disc whenever anything crosses the air gap, in either direction. No disc makes a round trip, and optical media has no controller chip to re-flash. Check each inbound file signature on the air-gapped side, not on the connected machine.
Split your password manager master key with Shamir’s secret sharing, so it requires two of three trusted people to unlock it. Never reuse a keyholder across vaults. Unlocking must happen in person to prevent deepfake frauds.
Treat every device in your house as a potential bug. No speakers or TVs in the office; put phones in a shielded locker outside the door, and run white noise whenever you type a passphrase (or simply continuously). Shield the room (conductive paint, copper mesh in the drywall, metallized window film) so nothing on your network can pick up radio, sound, or light leaking from the air-gapped machine.
Remember that none of this helps once a bank’s own servers get hacked. You can try spreading across many banks or just withdraw everything in cash and stash it in your shielded office, where it’s safe from everything except fire, flood, burglars, bailiffs, moths, mice, mold, people, pets, in-laws, and inflation (this is not an exhaustive list). Gold mitigates some of these vectors.