I think lately there has been this concern from many folks that copycats are taking away some market share from indiehackers. A post was made on indiehackers as well recently related to this. So I feel that people would be hesitant to share. I personally have come across couple of indie hackers who stopped "building in public".
I love threads like this - while I've stopped sharing my numbers in public, I've watched folks blindly copy my uptime monitor's landing pages and then close up shop 2-3 months later when they haven't gotten rich fast.
At this point, being comfortably full-time employed and using that income to let me play all-in-one Founder/Designer/Engineer/Customer Support over the past few years is the moat.
It can be an antagonistic environment for online businesses, a surprise for the starry eyed hacker or entrepreneur who just wants to build cool stuff.
We regularly had competitors running negative SEO campaigns back when that was easier, we had review bombs, DDOS attacks, network incursions, you name it. Building out of the public's eye doesn't really stop that once you are actually operating, your competitors will find you.
When you build in public, you share more than what's on your website. You tend to share tactics you used, even vaguely. It may have taken you months to get there and you're making it easier for others to catch up. Or so some people believe.
I think giving the recipe away is not a worry as 99% won't execute it, or won't do it as well anyway.
