When you’re going from Swiss cities to Paris, most likely on business rather than vacation, sometimes time is more essential than viewing the scenery, even with the TGV Lyria (dumb name) purportedly making the journey from Paris to Zürich in four hours.
None of the rail companies in either France or Switzerland are privately owned; they’re all owned by the state.
These euro trains are ridiculously expensive especially if you aren’t travelling alone. Rental car is the way to go.