I’m mainly posting this (in Offtopic) to rant and commiserate.
On my machine (Chrome on a Mac laptop), Stack Overflow is mostly unreadable now. The text is too small, and if I zoom in the formatting gets all wonky. And the worst part is that the font within the code chunks is far too small and narrow. Only about half the column width gets used inside code chunks now.
Here’s an example of how it looks on my machine:
Look at all that empty space on the right half of the code block, because the font in the code block is so tiny…