Remind them that offices used to be filled with people typing on electric typewriters all day.
There are ways to make a keyboard more silent. We have a
wiki article about it, but not all methods can be applied to all keyboards.
One common and quite effective way for most Cherry MX keyboards is to use O-rings or
QMX clips (even better)
QMX clips were made to fit a specific set of keyboard models: They require switches to face south, and luckily the switches do on the Varmilo VA109 Mac. However, they were made for Cherry-profile keycaps, and I'm not sure if VA109 Mac's keycaps are compatible with them without requiring extra O-rings as well.