Also if that can be useful, I got to use a few different versions of the 15” through a series of replacements which allows me to compare their relative loudness. The one I currently own is a 2019 i9. It is generally decent. My workload is mostly Xcode, Qt creator, an unreasonable amount of Safari tabs (10-100), Ableton, and Max while only having the fans running hard occasionally. Most apps are fine, but some are problematic (Qt creator especially, which has a terribly nasty macOS specific performance issue / bug). I can run Ableton for a while quietly, but fans generally kick in after a while if I’m using a few tracks & effects (I don’t use plugins, only stock Ableton effects). The 2018 i7 and 2018 i9 I got to use for a few months were much worse than this, the latter being the worst. The fans would be quite audible when running a even a completely empty Ableton project.
Edit: I also remembered that the 2018 i9 benchmarked worse than the 2018 i7 for demanding multicore tasks (3D rendering using Blender Cycles) from my testing.