Agreed, it’s super useful for day to day stuff.
Take a thought like “I took too many hints in that interview question.”
That thought might lead to “I must have failed that interview” which leads to “I’ll fail all the rest of my interviews” which leads to “I’ll never get another job” which leads to “I must be really bad at this, I should just give up.”
Each step seemed kinda logical at the time, but one thought led to the next and now you feel awful.
CBT is a counter measure to this; it stops you at that first point and gives you a bunch of common logical fallacies that help you recognize why your thought is overreaching. You don’t know if you really flunked that interview, besides flunking one is good practice to pass the next one.
That thought process isn’t exactly a mental health issue, but it’s common for people to suffer from. You don’t have to feel that way, and CBT is a way to have a much more stable and healthy emotional state.
It turns out that most of the bad thoughts people think about themselves are wrong, so as a therapy you work on correcting that.