Building platforms
One of the challenges of being an indie author (or an indie anything) is building a platform. Best estimate, from some very knowledgable industry know-bobs, is that it takes 12 months to build just the stubbled foundation of a platform. That's 12 months of posting to social media sites, writing blog posts (yours and guest posts for others), making YouTube videos (if that's your thing) and generally trying to very gently convince people to hang on your every word.
It's not an easy process, and not always pretty. Plenty of mistakes will be made. And the fruits of your labor aren't always evident.
I've spent years blogging to thin air, or so it would appear. But when I check numbers and metrics, I see that I do have an audience. Your a quiet, respectful bunch, to be sure, but you're out there. You like and share my Facebook posts and retweet my tweets and even, occasionally, comment on my blog. Though that last one has start to fade in the past handful of years, largely because there are so many other and BETTER ways to interact with me.
Is the blog dead? I don't think it is. As an SEO machine, blogs are invaluable. As interaction with an audience, not so much. Not these days. Think of any blog you follow, especially if it's popular and garners tons of comments, and thread your way through it. How much interaction are you really seeing between author and audience there? Scale makes it nearly impossibly, eventually, to respond to every comment. Sometimes there's trolling that warrants no response whatsoever. Sometimes it becomes apparent that comment threads are where OTHER people are building THEIR platforms.
Keep the blog, for SEO reasons if no other. I'd also argue to keep it as an outlet, and as practice. But increasingly, social media is the platform that any content producer will have to rely on, almost exclusively, for reaching and interacting with an audience.