For booking flights etc. I applied for my first credit card twenty years ago, and chose the lowest credit limit, which was £1,000.
I always paid it off monthly, so never paid any interest.
Even though I never requested it, my limit kept creeping up. Today it's thirty times what it was originally, even though I'm living on greatly reduced circumstances, and am offically retired, and living off a pension.
If I start believing the nutters with placards, that the end is nigh, and they offer a little more proof, I might blow the lot go and on a massive spending spree.