"Isolated profiles" is a phrase every profile tool uses. It's worth knowing what it has to mean to be worth anything, because the word covers a wide range of thoroughness.
Weak isolation separates cookies and calls it done. That leaves several other ways two profiles quietly reconnect.
The layers that have to be separate
Storage
Cookies, yes, but also localStorage and IndexedDB, two places sites write persistent data that outlive a cookie clear. If two profiles can read each other's localStorage, they are not isolated, whatever the cookie situation.
Network
If both profiles leave your machine down the same connection, they share an exit point. Real isolation lets each profile run its own network path, so one context's traffic doesn't share an origin with another's.
Environment consistency
A profile configured for one region should behave like it belongs there, in timezone, clock, and language, without you setting each by hand. A profile whose stated region and actual settings disagree is a profile that stands out.
Session state
Nothing written in one profile should be visible from another. Full stop. That is the line between profiles that are genuinely sealed and profiles that merely look separate in the interface.
Why the browser underneath still matters
You can isolate all of that perfectly and still be running a browser that behaves oddly at the network level because it was rebuilt to alter what it reports. Isolation and authenticity are two different problems. Getting one right doesn't fix the other.
The Chameleon Hive approach is to solve both at once: real, vendor-signed browsers for authenticity, and full per-profile isolation across storage, network, and environment for separation. Cookies, localStorage, IndexedDB, and network state are separated per profile, and timezone, geolocation, and locale sync to each profile's settings automatically.
The test
Ask of any tool: can profile A read anything profile B wrote, at any layer, anywhere? If the honest answer isn't a flat no, the isolation is partial. Partial isolation is the kind that holds until the day it doesn't.