what with - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Taking into consideration, because of, as in What with all you have to carry, we should take a taxi. This usage replaced the earlier what for. [c. 1600]