Hi Tajmo58 -
Now that others have given you the excellent reasons to use the trains, you may find this map useful.
I have zoomed it to zoom level 32 ( last number in the URL) at which magnification the train lines show up clearly as black lines.
(That is why I prefer this map to Google Maps.)
In the frame I've selected, you can see some of the lines near Interlaken, and barely see the line along the shore (through tunnels) between Spiez and interlaken
If you zoom out to a reduced magnification, this version shows that Bern, Luzern, and Brig (in the Rhone Valley) are within easy reach by train, often on quite scenic routes:
If you zoom back in, the train lines will reappear. You can see that there are several routes to Bern, allowing a choice of different "to" and "return" routes.
If you zoom in south of Interlaken, toward the Jungfrau, you can see the train lines and the cable ways:
Cars cannot even reach some of the locations along some of the mountainous train routes, and everyone in the party gets to look at the scenery. No worries about driving. Cars are not permitted in most of the near near the Jungfrau.
I took the attached view of the Lauterbrunnen Valley while standing beside the train line as it enters Wengen coming up from Lauterbrunnen. You can see the same view from the right side of the train as it pulls into Wengen station. ( that is, you can see it if you have clear day, and in December, there will be a lot more snow, although the valley floor may not have any). Wengen is a car-free village.