The problem with traveler’s checks is that few places really accept them anymore and those that do charge a hefty transaction fee.
They are often not worth the trouble for tourists. First, getting them from a bank (and paying a fee); then, trying to find a place that will accept them. Credit cards and money are much better for most travelers.
I use to use them but when I spent most of the day trying to find a place to accept them (and not charge a hefty fee) I gave up on them.
I first used them in 1979, as I left a base in Germany and closed my on-base bank account. The transaction fee, I felt at that point, was a bit hefty. That was the last time that I ever used them.