Various scripting languages used as syntax for generating web pages support functions and parameters that are not universally recognized by web browsers. Even though the Firefox browser is one of several browsers that are in common use in the mainstream, only it recognizes a particular property called "@counter-style" that lets the author manually define a way to make numbered lists display the numbers as entirely different symbols. Considering how a browser being unable to fully parse pages that competing browsers have no trouble with would negatively affect that browser's image, one would be forgiven for being confused as to why browsers do not automatically support as many obscure and potentially creative forms of syntax as possible.
It can be theorized that this phenomenon is at least partially owed to how each browser was originally formed to provide a different service that serves particular demographics that the existing browsers of the time had not adequately served yet. For example, Google Chrome places extra focus on expanding its own functionality and potential to match the ongoing evolution of Internet technology as a whole. As much as a browser's original mission can influence the types of syntax it can support, however, it also happens on many occasions that accomplished programmers craft original functions and insert them into browsers mainly for experimentation's sake.
The individuals composing the development team unavoidably form a pool of talent that cannot be duplicated by any other team, and this can be influenced just as much by what exactly is allotted to the team for it to work with. The budget devoted to a particular project will naturally define what is realistic for a team to create and how ambitious it may consider itself open to being along the way. Furthermore, the order in which a web browser or another program's features are developed is significant because features are often interconnected. Other features often use existing features as a foundation, so a feature will likely shape the final form of other features developed in the future by making certain concepts those features could use harder to realize than others. For more information click here https://www.reddit.com/r/web_design/comments/awq07u/whats_the_logic_behind_browser_support_and_why/.