Why do they want you to use it? Because it ties you into them thus becomes more expensive to use and has a lot of in-flexibilities. Pay if you want more flexibility. Pay if you want to back up your site. Pay with time if you want to transfer your content to a different host. Weebly is easy to make a website and used to have the advantage that it was mobile/tablet friendly but now it is absolutely and categorically crap for doing anything else. WordPress, Joomla and Drupal all have mobile/tablet friendly interfaces for creating content.
So my website blogging has been delayed until I have evaluated other content managers. I have been reading and am now trying to recreate my site in different content managers: So far this is where I am up to:
Drupal: If you are a total geek you will install on your own web-server and play with it for days. Currently testing Drupal on Pantheon servers and this has greatly increased my like for it: https://pantheon.io/ However it is still very technical and thankfully I am able to play from having played with IIS, SharePoint, and Dreamweaver.
Joomla: Really like the interface and the technicalities. Wish I had used it in the beginning. I am using Joomla directly at www.joomla.com and here is my first attempt at porting part of the site over.
Copying and pasting from one site to another is time consuming and all links will need to be changed. However it does a pretty good job of it. Also backing up seems pretty easy as does creating pages and such.
WordPress: I read a lot about how WordPress is a beginner's tool and is not very technical. But I am having fun using it and see the site admin is nearly as technical as Joomla. I am using WordPress from WordPress.com. Gotta sort out some glitches with my web hosting site before I can