Q 1 Is any one of this is by default included in Rails ?
Q2 Any advantage of this gems over simple form tags ?
For me, most of the time there is not, actually they add overhead IMO
(at least for my purposes) so I actually just build meta-form-wrapper
helpers that generate generic left_text_area and other methods like it
that just add the classes I need for forms and wrap the <section>'s
around the generic helpers that Rails already provides. That is,
instead of including another dependency that I don't need, but for
some people they bring great benefit because they can handle HTML from
step 1 to end, I don't like that because I prefer to directly control
every bit of output my app makes.
Only you can evaluate whether or not they are worth it, it's a battle
of your own to fight, I can honestly say I would use them if I
actually had a use for them, and many people will agree they have a
use for them, but I personally don't have a use for them so I choose
not to use them. You have to evaluate that for yourself.