I haven't missed an episode of The Daily Show in years, and Stewart seems like a very intelligent and informed person, who would be capable of doing a much more serious, ambitious show. On TDS, it usually only shines through when he has the right interview partner.
I enjoy both TDS and The Colbert Report, but I don't agree with all their views, or all the ways in which they express them and depict the other side. It's fun and can be informative to various extents, but it's also quite biased, and in no way real news. Even if you happen to agree with them, don't just rely on them, and take everything with a grain of salt. The people for which they are the main or only news source scare me. Then again, this might just be a symptom of the sorry state of US news in general. If fake news seem to deceive you less than "real" ones, and to actually inform you about what's going on in the world instead of only hitting you with propaganda and "human interest" trash, fake news suddenly become a trusted and reliable source. But I'm sure a lot of people also just appreciate getting their existing opinions confirmed.