I wouldn't say it's easier. Many gardeners start plants inside, though, so it's common practice. The advantage is that starting inside effectively makes the growing season longer. The disadvantage is that the plants need to be hardened. This is also called "hardening off." Here's a quote from a Google page:
The plants can't be set outside in a single day. They should be set outside for a few hours at a time till they're able to adjust to the outside environment. How that happens depends on the plant and the weather. For example, if it's still cold at night, they would need to be brought in to a warm room for the night.