If your computer is "breached" then it doesn't matter where your passwords come from. They could just run a keylogger and get them that way. It really depends

If your computer is "breached" then it doesn't matter where your passwords come from. They could just run a keylogger and get them that way. It really depends on your threat model. No system is perfect and we're mostly balancing security and convenience most of the time. The same password everywhere is super convenient, but only one site needs to fail and it's all over. A cloud password manager with unique passwords protect from that. A local password manager eliminates the threat of them being compromised, but is less convenient if you have multiple devices. Storing your passwords offline on paper in a safe protects your from someone getting read access to your PC or outright stealing it, but is annoying and gets more inconvenient based on your passwords entropy.