Credit cards have good protections against fraudulent webshops and often provide free insurance against damage and theft. This makes it worthwhile for buying a new laptop.
My card is automatically fully paid off at the end of the month, so mhe debt is very temporary
Don't rule out coincidence.
The odds of you and 4 colleagues getting the same disease by chance are really low. The odds of that happening to some group among the billions on this planet is a lot higher