You pay egress fees either way but the Cloudfront fees are lower.

I believe Cloudfront also still has a free tier which cuts out egress fees on the first X GB of data.

most of the time it doesn't. Their free tier is very generous. You get the first 2TB of traffic for free (vs 100GB of free traffic if you use only S3). traffic above this is also cheaper than the price you pay for traffic directly from S3