Slow UI / low frame rate / choppy graphics on macOS

I’ve seen this kind of issue popping up on forums in the past: [1], [2], [3], [4]. I just started a new mix with about 20 channels and no plugins (yet) and I’m getting around 2-5 frames per second of screen updates. (I estimated that by looking at the time and seeing how many decimal point updates I see before each second change.) I’m running Ardour on an Intel MacBook 2020.

Model Name: MacBook Pro
Model Identifier: MacBookPro16,2
Processor Name: Quad-Core Intel Core i5
Processor Speed: 2 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 512 KB
L3 Cache: 6 MB
Hyper-Threading Technology: Enabled
Memory: 16 GB
System Firmware Version: 2069.40.2.0.0 (iBridge: 22.16.11044.5.3,0)
OS Loader Version: 582~1565

The issue seems reproducible. What kind of troubleshooting can I do to find out what the problem might be? So far I followed these instructions to get crash stack traces on Linux, but here’s it’s more like a performance problem rather than a crash problem. Any ideas?