I was 39 when my first book came out (and in my mid-30s when the anthologies I edited were published) and my writing is so much better now, and will be even better in the years to come.

30 is the opposite of an expiration date. You're only getting started. https://twitter.com/truestorydesu/status/1254263714259169280

The "failure if you aren't published at 30" is the body dysmorphia of writing.