Not to pick on you specifically, but I'm not sure why people accept that they suck at interviewing. It's an extraordinarily valuable skill that can be practiced. Say you spend 50 hours this year training on how to interview better and then search for a job next year. You could easily increase your salary by 20% and realistically 50% or more by going from a bad interviewee to a decent/good one. It's the single most valuable thing you could do this year.

Translating to raw numbers a US developer could effectively get "paid" like $1,000 an hour for doing training. Over your career that snowballs into an order of magnitude more.

They are referring to the coding portion most likely. You need much, much more than 50 hours to improve although you are right it can be practiced and is surely cost effective.

While you want to do your best, the key is to remember that the world is not going to come to an end if you fail that interview. For me, becoming too results oriented (am i going to get this job mindset) vs process oriented (how do I get better at interviewing and take each interview as a practice session) helped. Is it easy in practice? No, especially when you know you could double your comp in certain companies and you can feel your opportunity slipping away during a bad interview but the worst case is that you go back to your cushy job and your family still loves you.