Excellent point Baneeta.
That's blessing and curse of the communications revolution caused by the Internet. Imagine you turn on your TV or radio, and there you see anybody and everybody who has something to say, saying it with no filter, quality control and/or any real accountability for accuracy, relevancy or aptitude.
The beauty of it all is that it has broken down most of the barriers - distance (anyone can talk to anyone who's connected), language (while most of the internet is still in English, most people who are online can communicate enough to exchange information in English or their language of choice), time (gone are the days where communications have to wait - no special delivery needed, no publishing process, no physical dependencies), cost (at little to no cost [to the author and end consumer] anyone can get their word out to the world. Free websites, blogs, hosting, etc. have made it very easy for people to say whatever it is they want to say). Take blogs for example - they're a fascinating phenomenon! (I have my own)
So what now? Well, in my humble opinion, the content of quality comes and will continue to come from 2 key sources.
1) Reputable sources - those who in the 'offline world' produce content that makes its way to the Internet in a documented, referenced and 'moderated' fashion.
2) Individuals with great knowledge - people who use the online medium to express thoughts, opinions and experiences with others. Sites like Yedda and Wikipedia, that focus on creating a self moderating and regulating community of people sharing knowledge are the best examples I can think of this. One caveat being that this continues to be 'personal opinions contributions', so there may not be an exact science to a medical tip or to a solution to a problem that may have worked for one, ten or a hundred people.
Self moderation is key in my opinion. There are ~1.3 billion users on the Internet and sites which promote an ecosystem where users and content are graded for relevance and suitability result in the most relevant experience possible.
The rest of the Internet can be considered 'for entertainment purposes' - one can visit countless sites with information, interesting, funny, educational, and any other number of adjectives I can think of... but like you say... its mostly irrelevant.
Happy surfing!