You can easily save up to 50% on your train tickets if you buy Saver tickets, but you're stuck with that specific train. Not good if you're not sure of your routes and timing but it's a great way to save if you're a super planned person. But yeah public transportation is very expensive here but at least it's super reliable and very easy.
Don't forget you can buy an "international traveler" half fare card", valid for a month, for CHF 120. If you intend to take a lot of trains and buses (albeit, for buses, it's not really giving you 50% off), this might be a good option to add. Just on a return Lausanne-Zurich, you'd save CHF 74 already. Just gotta make some calculations in advance to see if it's worth it for you.
https://www.sbb.ch/en/leisure-holida...fare-card.html