Surprising, but you really don't even need an M1 for those programs. You want fast external SSDs, though. I use the last Intel Mac mini for audio things, and it's fine.
For example he mentions FL Studio can handle 70 tracks of Nolly. The latest FL Studio version's tutorial project has 98 tracks and can run on an HDD if your CPU is fast enough. The effects being used are lighter than the Nolly guitar amp effect. But they're still more cpu heavy than I/O heavy.
The SSD matters for picking the sounds, in my experience. So you're going through listening to a bunch of drum hits, for example. If the drive is slow, this stalls.
Plus, isn't he simultaneously playing 70+ tracks with a CPU-intensive filter on each one? That's not a realistic workload.
I linked this in another comment, but here's a real video of a Skrillex single and it has 180 tracks loaded with plugins.
He mostly uses virtual synthesizers, but you'll notice the track is mostly composed of audio clips and not MIDI running a real synthesizer. Because he does the synthesis in a different project and renders the audio out. Because it would be impossible for a project like this to run in realtime with the synthesizers being calculated.