What are some good websites for writing?

The first thing that popped into mind is Wattpad, which you might not want to get into since it does have... a reputation. But it IS the writing platform with the biggest reader base as far as I know, with works often getting millions of views especially if they're not paid. Wattpad also has awards like the Wattys as well as (I believe) genre-specific awards. Some genres like sci-fi don't get as many readers as, say, the romance section, so you'd have to remember that with websites like these, you're dealing with a trope-hungry audience who probably value a scandalous plot over good writing style and character depth.

If you're thinking of nonfiction articles or similar, Medium is a good site to use. Plenty of people have essay-type articles on any topic that interests them, from food to travel to pop culture, and the best part is you can get paid for your articles.

If you're interested in writing fanfiction, that has an even bigger audience since with original works, people often stick to published books, and with nonfiction, there's already so much out there. Sites like fanfiction.net and archiveofourown.org also have lots of traffic, especially for popular media or franchises. Another bonus is that fanfiction is a lot less 'background' work like worldbuilding, creating characters etc since you're basically just playing with established storylines, characters, and plots and choosing what you want to keep.