I've been blogging in some form or another since the late 90s, but consistently on the same blog for going on 15 years.
Like many here, I turned off commenting years ago. My motivation had less to do with spam. (I'm on WordPress and it does a pretty good job with that.) It had more to do with the conversations moving from my site to the social web. Folks wanted to talk about stuff where they already were, rather than centralizing that conversation on individual blogs.
(As an aside, I rarely participated in those comment threads on my blog. I always saw them as a place for others to talk about a post. I'd already had my chance to say my piece. So the comments had less value to me, personally, but seemed to have value to the folks reading my blog. All to say that I wasn't really driving engagement with the comments. I was just letting them do what they were doing.)
I tried a few of those "commenting" solutions that attempted to pull the social channels into the blog itself, but they never seemed to recreate that 2005-2010 dynamic of active and engaging conversations occurring on a single post.
It's also worth noting that, in my experience, a big motivator for many platforms had to do with driving pageviews. And once commenting stopped doing that, folks seemed to lose interest in continuing to offer that functionality.
I have been blogging for twenty years, unfortunately, not on same blog though. But I was also using WordPress and comment spam was virtually nil.
For me the big issues was lack of comments. It made my blogs look like no one was reading them. So I turned off comments.
Then I realized all other functionality of WordPress was geared towards businesses or marketers. I don't need every blog post to automatically spam all of my social networks. It was just extra work to keep WordPress secure and updated.
So I moved to static site generator, and if I want to share certain posts, I will manually share with friends. Much better engagement and comments this way.
My blog dates back in some fashion or another to some point in the 1990s and before the word "blog". It's been through so many different technologies. The only "off-the-shelf" one used Drupal for a few years. Most of the rest were bespoke. Many versions and archives have since been lost though I've tried to keep continuity where I can (the current blog has some URL redirects all the way back from the second version on Drupal after the last major loss of archives).
When going bespoke again after Drupal I decided to outsource comments (to Disqus) knowing full well from previous versions the spam problems and the tools to fight it. That was for a Python/Django blog engine I wrote and used for a few years. I've since moved to an SSG (Jekyll for ease of Github-automated build process; maybe I'll revisit now that Github Actions exist).
A few years back I decided to eliminate all trackers and deeply audit third party JS code on my blog. Disqus of course did not pass the bar I set for myself (and my current feelings about privacy and ad tracking) and I thought I'd replace it with something bespoke maybe, put up a "temporary" warning that comments are currently gone, but I just haven't and I haven't really felt much pressure to. At this point I'm not sure if I should. I miss comments some, but the heyday for comments on my blog was during college (in "the Google Reader era") and was never quite the same since.
I still have the dump of Disqus comments and there are at least a few historic discussions in there (some of which themselves were migrated out of Drupal back in the day) I keep thinking of trying to repost them somehow on the relevant posts, but keep procrastinating that idea as well, in part because I don't know if/how I will turn comments back on in general. I'm not sure if I even need to at this point. I keep wondering if I miss comments only for nostalgia's sake and that era is now so far in the past anyway that there isn't much to gain in the current era with comments on blog posts.
Like many here, I turned off commenting years ago. My motivation had less to do with spam. (I'm on WordPress and it does a pretty good job with that.) It had more to do with the conversations moving from my site to the social web. Folks wanted to talk about stuff where they already were, rather than centralizing that conversation on individual blogs.
(As an aside, I rarely participated in those comment threads on my blog. I always saw them as a place for others to talk about a post. I'd already had my chance to say my piece. So the comments had less value to me, personally, but seemed to have value to the folks reading my blog. All to say that I wasn't really driving engagement with the comments. I was just letting them do what they were doing.)
I tried a few of those "commenting" solutions that attempted to pull the social channels into the blog itself, but they never seemed to recreate that 2005-2010 dynamic of active and engaging conversations occurring on a single post.
It's also worth noting that, in my experience, a big motivator for many platforms had to do with driving pageviews. And once commenting stopped doing that, folks seemed to lose interest in continuing to offer that functionality.