Do I need a MACRO lens?

And at the other end of that focus range is, of course, you.

You are using a wide angle, and of course with one of those you can get much closer, even without a macro, than say a 135mm. With a macro you would get even closer, and would say be able to take a photo of a single flower, or part of it.

And just as with non-macro lenses, there are characteristics of say a macro focusing longer lens, which you might want to use if you want a shot of a single flower, but say it's  a meter away from you. Or perhaps you wanted a photo of an insect on that flower; get too close and it will fly away or bite your nose. So you use a 100mm macro. Those lenses are also sometimes preferred by people taking portraits too. And the distance you can be away also comes into play if you have to use artificial lighting, or a tripod (pretty necessary with most macro shooting).

There can be some downsides with macros, like focusing ability, sharpness, max aperture, etc. But having one can give you a new range of possibilities. I've managed to find some nice macro primes with manual focus to use with adapters, that didn't cost me a whole bunch more than even a macro adapter like the Raynox. I didn't find the manual focus much of an issue with close up stuff, and they are quite fun to use. You can walk around in an otherwise dull setting and find all kinds of stuff to photograph that you otherwise wouldn't pay attention to, even if you don't get into 1:1 shots.