Would it be bad if I only Publish 4 Books or Book extensions my entire life?

I have three ideas that can be turned into a series where more than one book could come from the series.

I have a fourth idea that could also be turned into a series, but if I do a series I might have to discuss more than one religion because my topic is limited to manuscripts for writing analysis and the manuscripts I plan on using right now are not that long.

My uncle says one good idea will earn me more money than 4 bad ideas and I need to prioritize the quality of my writing over the number of books I write.

Dan Brown and Margaret Mitchell are both people who made a rising using only a modest number of Written Creations.

Would it be bad if I only Publish 4 Books or Book extensions my entire life?
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