peaceandquiet – Unfortunately selfish people live everywhere – in strata high density units, in strata low density units, in semi detached dwellings, in detached dwellings, in suburbia, in cities, in country towns, by the beach etc. It happens.
Strata by-laws have noise and nuisance provisions but sadly not all occupants all of the time abide by them.
Have you gone through all of the steps here:
https://www.epa.vic.gov.au/your-environment/noise/residential-noise/noisy-neighbours
Are the noisy neighbours tenants, or are they owners? If they are tenants can you contact their Agent?