Earlier quoted context omitted.
I think they meant that there isn't really a freelancer visa, so most people would have a chicken and egg problem. AFAIK you can run your own business with a B permit which is in turn justified by income/employment in that business, but you would usually transition from a permit through another employer or other types of visas (family, student, etc.) I think waiting until you had a C permit would be more common, espe…
I wouldn't need a visa as a German ( or any other EU national ). If I want to work ( as employed ), I would need an "Aufenthaltsbewilligung".
If you are German then no one should have told you there's no possibility of freelancing, but it might make more sense to first take on enough Swiss customers freelancing from Germany, or as a commuter to Basel, etc. I would just recommend being conservative about maintaining a reasonable/stable salary sourced from Switzerland when renewing a residence permit.
If you really mean contractor gigs from abroad, everyone I met doing that actually works permanently for a placement agency, and most of them are not very nice. IMO it is just as easy (or hard) to find a job directly and better.