Update: This problem is apparently fixed. I recently – a couple of days ago Jan 2, 2025 – updated VirtualBox to the latest, and installed a Linux system and updated the guest additions using the new Virtual Box. And the resolution of the display was fine. So looks like they fixed it. The guest additions I saw were 7.1.x, not 7.0.x. Not sure where the fix came in, but it looks like all is well.
I checked the version of the Guest Additions in the Linux Mint virtual machines and the Blurry Problem is apparently caused by the 7.0.22 Version of the guest additions. See the earlier post to see the blurry text. Have a look at the GA versions in the following logs:

This is the earlier version of Linux Mint with Guest Additions 7.0.6. Text is not blurry because the window can be resized to fit the screen resolution.
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