I never bothered with a CC until I retired. Mainly a Coles MC for the Flybuy points. They just gave me a $5000 card without me asking for any particular limit.
I asked St George for one just to see if they would and they gave me a Visa for $2600. Like you, I only use them for convenience and as a backup if needed.
Handy for things like hire car and so on, so your Debit card isn't tired up for days.