Honestly I expected lower numbers. The title seems a bit negative, but let me rephrase this as: if you make 6 diverse enough apps, one of them could give you non-trivial monthly pocket money (or income if you live in a low CoL country). Once you know what you're doing, trying different 18 apps may land you a decent global income. (This assumes single creator apps)

It's not amazing, but... that doesn't sound too bad, right? You shouldn't drop everything and start an app development studio without a good buffer, lots of spare time, or a separate day job, but that's higher chances than people jumped on with many startups.