The fivethirtyeight website which I think is most reliable for polling as it's a weighted aggregate of polls based on the strength of each shows only modest growth in approval with Trump still deep underwater overall.
What you think, frankly, is irrelevant. I was citing a recent poll from the New Yorker, hardly the equivalent of Fox News or a non-credible source, that showed Trump's approval rating was up by 10 or so points, with the support coming mostly from independents.
While it may or may not result in a Trump re-election, it's clear that the impeachment proceedings have generated a positive bump in approval for the sitting president. Interesting development and the opposite of what one might expect.
At the risk of offending you further by offering my thoughts, I think you may be confusing a Gallup poll published in New York magazine (but not their poll) with something in the New Yorker.
Here is the latter, which actually quotes another very reliable and highly respected aggregate poller, realclearpolitics as showing that impeachment has hardly moved the polls at all, though that was a couple of weeks ago:
New York magazine however shares a newer Gallup poll showing Trump's approval rating is up 6 points (not 10 though) since the start of the impeachment inquiry. That story is here:
Though neither shows a jump of 10 points as you claim above. So perhaps there is a newer New Yorker piece that google couldn't find.. Or another magazine with New York in the title perhaps? Or perhaps you meant the rather consistent 10 point gap between Trump's unfavourability and favourability ratings (52.8/42.7) as shown here:
Whatever the answer, feel free to share the link to the 10 point rise you mention above.
Also, contrary to what you suggest, based on the only recent example at least, it should not be surprising that Trump's approval rating has risen since the impeachment as the same thing happened to Bill Clinton, based on Gallup's polling then:
"the onset of the publicity surrounding the Lewinsky revelations was correlated with a significant jump in Clinton's job approval rating, and the two quarters during which the House and Senate debated impeachment and conviction -- 4th quarter 1998 and 1st quarter 1999 -- saw the public give Bill Clinton the highest job approval ratings of any of the 25 quarters of the Clinton administration to date."