Buses, coaches, & lorries

I don’t very often go by bus these days but last week, to save my daughter collecting me from Fareham railways station, I caught the bus to Gosport.
This single decker of 2016 vintage was horrendously noisy, not only from the engine/hydraulic gearbox but the clunking etc of the chassis.
How do bus builders get away with it? Surely better sound insulation from the rear mounted drivetrain would be possible?
I reckon my 1980 F12 was quieter by far!
The gearbox was the producer of most of the noise!