One thing for sure: Aespa can sing. But the management want them to lipsync either they want Aespa to be perfect or they don't want to regress their voices.
Also, they don't want to overwork their idol since not only they practice their dance or their vocals for their upcoming comeback, but also they doing acting for SMCU, modeling for magazines, being ambassadors in different brands and many more. That's why they only send to 2 music shows from the usual 4 music shows.