It has been so long ago that I've been on the local buses, I had to look it up.

That calculator does miss INSURANCE. And, a mentioned, depreciation depends a lot on the age of the vehicle. Older vehicles can require more maintenance, but spare parts can also be much cheaper. Depreciation is both age + mileage.

Anyway, for our local buses.
Lane Transit District
$1.75 per fare
$3.50 day passes
$135 for 3 month pass

PLUS
$7 per thousand payroll tax.

So, for a person earning $100,000 the payroll tax would essentially double the fares. For someone earning under $20K, it is less significant.

For me, getting to the bus line is just not practical, so it doesn't provide me much benefit.

Here are farebox recovery rates around the globe.
https://en.wikipedia.org/wiki/Farebox_recovery_ratio

Some of the Asian systems actually turn a profit. Many 3rd world nations aren't listed.

There are many private Jitney bus systems around the globe. I presume most are self-supporting, and turn a bit of a profit.

How can a Jitney be self supporting while a municipal system can't?