web 2.0 gernally are of low authority so should I do web 2.0 or not?

I'm going to write no because you added "low authority." To me this means your goal is not about Web 2.0 at all as defined at https://en.wikipedia.org/wiki/Web_2.0

That is, if your needs are SEO and not participating in the discussions, adding your content then no, it's not good for you.

In past, web 2.0 site were used to make backlinks but now they are not effective as before because people make many accounts and than put low quality content (Spin articles from articles sites) on them and try to get backlinks from there so try to avoid it.

Today’s SEO is all about Quality content, if you have good traffic on your web 2.0 blog and also have good quality content than it may be helpful.

I think at this particular time Google is becoming more smart and achieving an anchor based link from web 2.0 is super easy. So why would Google give it a value if everybody can make these kind of backlinks. I hope you understand

web 2.0 doesn't help a lot. The thing you need to do is join your niche community. Engage with them, share your thoughts. Build your reputation over there. Then finally it can help you.

This is nothing but an extended version of web 1.0 where we focus not only on creating backlinks but getting a good amount of traffic also.So, Web 2.0 Is good .

Yes web 2.O is good. But nowadays the new techniques work properly as like Video sharing and infographics.

Yes, web 2.0 is very importent and useful for ranking your website in google.

Web 2.0 submission is the online technique. In this, you can share your content via hubpages, squidoo, blog sites etc. Web 2.0 submission is the way or technique to share your content through different blog sites.

Yes, Web 2.0 is good. It is important in building simple things that people can use.