I ran a newsletter back when I first started writing in 2016 or so. It used tinyletter and had about thirty subscribers. Most of these people were family members. I based it off a model used by Abi Jones because I liked her layout and the content was both personal and industry related. That worked well for a few years while I was writing Redbriar and pretty much put the newsletter on pause a few months after publishing the book. It was still the same 30-40 people. The same folks I could just share the info with on Facebook or Twitter or legit email. (So why bother with the newsletter at all?)
After a while I thought it would be a good time to start it back up using substack because it was new and had more features than tinyletter. Half the folks who had signed up for the first one didn't sign up for the new one, and those that stuck around clicked on zero links. My content was the issue. I couldn't come up with anything to hold someones attention the way it's required to have a successful newsletter. So I went back to the blog.
I tried doing a little post here and there on my main site, using the wp install as it was intended. The content again became an issue because I'm not an industry leader nor do I have the one-hobby content-creator lifestyle. (If you are either of these things then the newsletter format will work out great for you.) It just clogged up what was basically a portfolio site with personal junk posts like this one. I needed a space to vent nothing to nobody without messing up my main site. (That's why this blog is here and not there.) Real work, projects, art, etc go there. Junk goes here.
Frequency was the other issue. The newsletter was once a week. I couldn't just post whatever thought I had that day on that day, I had to wait and fit it into the email somehow and usually by then anything I wanted to mention was old news. I kept trying to theme the things, keep them relevant to what was going on, or what wasn't. Creating the newsletter became more time consuming than everything else.
So, about your newsletter. I will totally sign up for it, link it to me, I don't mind. They are important tools these days, and I understand. There is a dedicated email address I use for such things to keep my main inbox under control. However, I check it once a month like I do my PO Box. That being said every morning and evening I do check my RSS feeds. If your newsletter has that option I'll add it to my reader and for sure will read it that way. I know substack and tinyletter have feeds and it's a good idea to link to them in some way in your email.