I think you are mostly right, but I'd rank it like this (from best to worst combo of quality for time + cost):
1) "high end" webcam (~$200)
2) DSLR + capture card you already own
3) Any Webcam
[...]
10) Buying a DSLR and capture card only for this
You miss out on most of the benefits of a nice still camera when you use it this way - 90% of people will have less trouble and cost by just buying a better dedicated webcam. That said, some people need a nice webcam and need to produce video content - they SHOULD use this setup (or at least try it). Purpose-made webcams are "bad" as general purpose cameras but good at what they are sold to do - deliver good enough video that you expect to get murdered by compression.
1) "high end" webcam (~$200)
2) DSLR + capture card you already own
3) Any Webcam
[...]
10) Buying a DSLR and capture card only for this
You miss out on most of the benefits of a nice still camera when you use it this way - 90% of people will have less trouble and cost by just buying a better dedicated webcam. That said, some people need a nice webcam and need to produce video content - they SHOULD use this setup (or at least try it). Purpose-made webcams are "bad" as general purpose cameras but good at what they are sold to do - deliver good enough video that you expect to get murdered by compression.