i think when mai asks katara how does she expect to fight without her bending, that reveals more about mai’s perspective as a nonbender to other benders (most specifically azula).
like the fire nation prized and upheld firebending (one could ask, has there other been a non-bending firelord?) and so mai would have grown up with that and also the realization (the dawning realization) that azula surrounded herself with nonbenders to feed her superiority complex.
fire nation culture told mai at every opportunity that bending (which seems to have been primarily coded in an imperialistic context, especially at the end of the series when azula’s answer to dominate the earth kingdom was to just burn it down and also their military has always been comprised as benders, i think) was what made people strong—mai probably believed that benders did not work as hard, did not train as hard as people like mai or ty lee did to fight — and when it’s gone, then what?
mai’s statement reveals that instead of buying into the idea that firebending was primarily the only strength that mattered, she sees bending as a weakness that can be exploited.