Go with the Pros
Articles are written by scholars
One of the best things about using subject encyclopedias is that the articles are written by scholars or subject experts. These scholars and experts were selected by editors, so you can be assured that these people are real (you can't say that about most websites). Their experience and academic credentials have earned the authors credibility.
We won't say that everything in print is perfect or true. People do make mistakes. But when you use materials that have gone through the publication cycle -- research, writing, submitting, editing, fact-checking, proofreading, and publishing -- you at least know that you're starting with quality material.