We have rented cars for our 3 previous visits to Switzerland one of which included a visit to Zermatt where we left our rental car for several days in the parking area at Tasch. That visit was actually our first Europe trip! Except for the one speeding ticket that found its way to me after we were home, I have no regrets that we traveled by car!
Driving in Switzerland is not difficult. Just be sure to have a Swiss Highway Vignette and obey the speed limits. In fact there are benefits over a train in that you can stop to take photos or spend time in one of the many delightful villages enroute. It is also enjoyable to drive some of the twisty, turny mountain passes such as the Furka and Susten. The car train from Kandersteg to Luekerbad through the Lotschberg tunnel cuts some of the driving time to reach Tasch.
Maybe take the train from Paris to Freiburg Germany which isn't far from Basel and return it to the Munich or other German airport. You can purchase the vignette as you enter Switzerland near Basel.