I've often wished that formatters had some threshold for similarity between adjacent lines. If some X% of the characters on the line match the character right above, then it might be tabular and it could do something to maintain the tabular layout.
Bonus points for it's able to do something like diff the adjacent lines to detect table-like layouts and figure out if something nudged a field or two out of alignment and then insert spaces to fix the table layout.
And sometimes, if the code doesn't look good after automatic formatting, the code itself needs to be fixed. I'm specifically thinking about e.g. long or nested ternary statements; as soon as the auto formatter spreads it over multiple lines, you should probably refactor it.
This was more about lamenting the need for such things. Clang-format can already somewhat tabularize code by aligning equals signs in consecutive cases. I was just wishing it had an option to detect and align other kinds of code to make or keep it more table like. (Destroying table-like structuring being the main places I tend to disagree with its formatting.)