Microsoft Edge loads your passwords into memory in plaintext, but Microsoft says not to worry
(www.windowscentral.com)
Chrome's handling is barely more secure. A compromised device will have a much easier time reading Chrome's encrypted store than scanning your RAM to find passwords.
Remember that if you don't need to input a password to open the store, then anything with access to your device can also read it.
Wether it's encrypted in your RAM or not barely makes any difference in how difficult the task is.
The only solution is: Browsers should require a password. Or even better: Use a dedicated, properly secured password manager.