They are untaxed in practice, so yes, the most favourable.

Cash tips were, for sure, but were also something you were supposed to report.

But now, tips are given with cards, and a record is kept of how much, and where it goes, and it is recorded!

So be wary, because you can be 100% sure they are taxable, and if you get audited...

Very much so, if you take them in cash and don't report them on your tax return.

Which is tax evasion, unless your tips are less than $20 per month.

Way back when I was in college, none of my peers reported tips. Has that situation changed?

It is tax evasion, but it was commonplace.

It always was illegal, but hard for the IRS to prove so most got away with tax evasion. These days most people pay with a credit card which means there is an electronic record that the IRS can demand of the employer. With cash tips the waitress was collecting the cash themself and the manager didn't have a good way to get the correct number. If you report zero tips in the cash system someone will notice, but if you report everyone only gave you half what they really did there is no way to know.

Yet this practice is nearly ubiquitous with cash tip jobs.

But again, it's not that simple, because everyone coming into your coffee shop is going to be expecting to have to tip, so you need to properly manage those expectations. How the owner is planning to do that, and the results of those efforts, is interesting.

Edit: and while per the other replies many people don't claim (all of) their cash tips, you are supposed to claim them as income.

Customers will tend to be price sensitive more to the listed price than the actual price they pay, particularly when it comes to tips since they're "choosing" to give the tip.

This would earn you the reputation of being especially expensive, even if customers aren't actually paying you more.