Because you're adding the execution overhead of MULTIPLE function and method calls. Because it encourages you to get that element every joe-blasted time you want to do something with it instead of storing a reference in the appropriate scope.
The code bloat of the train wreck of developer incompetence that is jQuery does not balance out with any ALLEGED savings it provides.
Hence why everything I've seen done in jQuery falls into one of three categories.
2) Things that could be done in a fraction the code without jQuery WITHOUT counting the size of jQuery against it.
3) inaccessible crap that has ZERO business on a website in the first place, and in certain industries could land your arse in court for WCAG violations under laws like the US ADA and UK's EQA...
... and that last one applies to most front-end frameworks including such gems of derpitude as React, vue, angular, bootstrap, tailwind, etc.
Don't believe me on the legal front? Ask Domino's and Beyonce.