Regarding formation of groups: same reason as humans, chimps and gorillas. Ants, bees and wasps are closely related to each other (compared to their relation to grasshoppers etc.) and evolved from a common ancestors which first developed this behavior.
These ancestors are so far in the past however that some modern species moved away from forming colonies. There are solitary bee and wasp species (not sure about ants).
On the other hand some insects, e.g. termites, landed on a similar strategy on their own. Similar to lions becoming social like primates while most other cats prefer solitude once fully matured.
Regarding non-stop productivity: individual members of a colony aren’t more active than other insects afaik. A hive seems always busy because they all work in shifts instead of 9 to 5. They also have a save hiding spot to chill so you don’t see them lazing about outside.
Latest Answers