Basically what the summary is. The resolution of the launcher keeps getting blurrier and blurrier.
Note: Each screenshot has a different area of the launcher that is blurry. 1 is the bottom (where it says "Play," "Settings," etc), 2 is pretty normal, and 3 is the top (where it says Installations and Patch Notes.)
This appears to be a duplicate of MCL-11059, which was later marked as invalid. Please see the duplicated link for further details regarding this issue.