Does it make sense to build a web app when dozens of similar ones already exist?

For example, I've been developing websites and small apps for a few years. Nothing groundbreaking. With the explosion of no-code/low-code tools there are so many more apps out there today.

I'm curious how people go about deciding whether to build an app or not, especially when dozens of other similar apps exist.

For example = there are dozens of property management tools, why would another one make sense? There a tons of tutoring collaboration apps, or stock trading log books. Many (if not all) apps already exist in some form. When is it worth building and focusing on something? How are people doing this?