When to stop daily blogging
You should really stop blogging when you think your time is better spent on another project.
Opportunity cost is a real one and hence it should be treated that way.
Time you spent doing one thing is time spent not doing another thing.
Update: I am breaking my daily blogging because I think my quality of work in other areas is getting down as I forced myself to post sometimes half-baked essays. I am going towards more research and depth. I also own a YouTube channel and (Hindi) Podcast hence it's hard to keep up with things. Because I can't practically produce 9 pieces of content each week while studying too.
But I still hold my belief that you should daily blog, as a habit of publishing online daily and making that habit of shipping. I have already made that habit so I find that justifiable reason to stop doing it. Now doing regular live podcasts solidifies it.