TL;DR: No, Twitter isn't very useful for either group.

I think Twitter is a good place to relax and watch everyone debate over the tiniest things. I get a lot of enjoyment from watching idiots yell at each other while both perspectives are wrong. However, I'm not entirely convinced it excels at providing developers or bloggers with what they really need: exposure. I recently posted a survey to my account, which only got 15 responses. A bit under half of those were from asking some dev friends on Discord, and I only got 2 responses before having some friends retweet. Twitter can't really provide an "out of the box" promotion or exposure space because the timeline and explore feed are already clogged up by kids thinking they know about politics or BTS stans canceling a random guy just to "stan loona." This is why places like dev.to are needed: it's a platform with a clear focus (I mean come on, it has dev in the name) where you can be productive and promote. In order to effectively promote on Twitter, you need to have friends who can bring you to a larger audience, but they need to have cracked the code already. On dev.to and webwide, it's a small enough community where you'll always get at least one view on a post or comment and it's not dominated by the BS. So no, I'm not sure Twitter can really help bloggers or devs without another platform.