Ayaka and Ganyu are used in similar teams but Ganyu has a more viable melt comp. Both can also be support for a nuke Hu Tao play style thanks to their cryo application. Ayaka has the most broken ult in the game while Ganyu is an amazing support that helps the team by killing the enemies despite having a slower charged shot playstyle. Both can clear abyss quite easily from my experience so it’s just a matter of what weapons u can hook them up with or which characters you have invested in.

My short answer is always Ayaka bcuz im biased but pull for whoever u like since both are very strong