From the point of view of 3rd party developers, if you plan to remove it, please do not do it. Make a search by “smarty support” on the forum and you will find many ways of using it.
Use it for all kinds of things. Personally, I'd rather see you remove the html block than the smarty block.
There are many potential custom uses that let you more easily provide custom content to a site. Many times it requires support from a controller to get the data. But that data might be local or remote.
Do not remove it. Why would you even consider removing it?