Traditional Fantasy alone is a harder sell in web novel spheres, there are a couple of reasons why in my opinion:
- You're up against people like Brandon Sanderson, lol. Web Novel readers don't tend to read fast food exclusively; there are plenty who still read traditional books too. So it's easy to imagine that someone who might like your work could just as easily read 'Way of Kings', 'Six of Crows', or 'The Name of the Wind' instead. It's not a coincidence WN authors that want to dabble in traditional fantasy elements tend to add trendy tropes to catch easier fish in multiple different ponds instead of only competing in the titan of an ocean that is Traditional Fantasy.
- Online readers tend to prefer a specific spice or two in their fast food. Going vanilla or experimental without the addictive substances like tables with arbitrary numbers, some loser getting splattered by a truck, or a line-up of waifus puts even more stress on the fact that your characters, prose, and plot have to outperform the competition who will gladly give people all the numbers, truck drive-bys, and boobies they want.
In conclusion, the online WN sphere is a niche climate. Traditional Fantasy readers have food for years, a massive smorgasbord of whatever they want by professional chefs. However, stuff like LitRPG and Harem tend to only be found on the web for the English side of the globe, either by online shopping or, well, finding it on a web novel site like here. Put simply, the target audience tends to be readers who already have specific preferences in mind. Going astray from this obviously implies risk on your part.