But personally, I found credit card useful:
1. safer - use bank money when shopping, not your own money. Avoid exposing your saving account.
2. some normal credit cards (e.g. ANZ First) offer 90 days insurance and 1 year extended warranty on some products (e.g. Appliances)
3. some service fees require credit card only
But, you must be a person who controls your expenditure well and shop reasonably within your capacity.