I can see that argument, but - it's kinda a philosophical question about "who the sender is". Is the the person who typed out the text? or is it the server which transcribed that text into N new emails?
The ML server will verify the original authors SPF. The N recipients will verify the ML servers SPF - the chain (which matches the series of MTA's involved) is still verified end to end.
> It'll break when used together with DMARC's alignment checks.
Yea, DMARC is a much bigger issue for mailing lists, but that's no reason to say "A mailing list will _always_ break SPF" - a well configured* ML has no issues with SPF at all.
* And, yes - the definition of "well configured" had to change when SPF was introduced, that's of course annoying, but there has been many many years for ML operators to make these changes.