Now, since my commute is rather short, I would certainly be cheaper off if I just had a subscription pass for my city's local transit and bought train tickets as needed, but it's such a vast quality-of-life improvement to be able to, for instance, decide on Friday to visit my parents for the weekend without any extra hidden costs.
(Caveat: All of this does not apply right now since I'm not entering any vehicles with other people until my vaccination has taken effect. But I'm still renewing my subscription because I already know the date when that happens.)
I know that that's only one thing, but the other similar-sized line items in my ledger are much more mundane (rent, utilities, insurance, and such).
[1] https://www.bahn.com/en/view/offers/bahncard/bahncard_100-co...