Plus are XML files likely to work on closed operating systems. Like video game consoles for example? Else what other popular file format would they use to store such data (excluding binary file of course)?
I've been reading about .ini files on wiki and they were saying that they've been made redundant, and largely no longer preferred. Apparently xml files are their popular replacements.
Hierarchical text data? Possibly.
XML is more commonly used to transfer data, though. For example, some websites have "APIs" that let a client application make a request for data. The format of the response varies, but it's often XML.
Plus are XML files likely to work on closed operating systems.
XML is just a text file. Even more generally, it's a text string. Any computer is capable of using XML. The operating system has little impact on this ability.
Else what other popular file format would they use to store such data (excluding binary file of course)?
There's no answer to this question. They can literally use any format imaginable.
I've been reading about .ini files on wiki and they were saying that they've been made redundant, and largely no longer preferred. Apparently xml files are their popular replacements.
INI files have one advantage over XML: parsing and generally using them is far, far simpler. If you don't need XML's sophistication, INI's simplicity is probably preferable.