Posting because most of the comments I read had a strong positive bias and I have a more lukewarm assessment.
tl;dr: I wouldn't suggest starting a blog for the purpose of getting some external benefit (e.g. receiving a job opportunity). But if you believe you'll get an internal benefit and you feel that benefit is worth the time investment then go for it.
Background: I started my blog "On Product, Tech, & Leadership" (https://blog.colinroper.com/) about 4 years ago to help me crystallize my thinking on Product Management and Leadership topics that I've learned over my career, and with the hope that it would help lead to future career opportunities.
So far it has yet to provide any meaningful external benefits (from what I'm able to tell). The site hasn't garnered much of a following or feedback, despite some modest marketing on LinkedIn. I suppose this is the fate of most blogs, though maybe my luck will change at some point. The blog has also has been a large time investment (in doses) to write the content, create the site, tweak the designs, and promote the occasional new posts.
That said, it has provided internal benefits. It has helped me clarify my thinking on some topics I care about. And despite not liking the act of writing, I have gotten better at it. Further, the time sink has been somewhat by choice: I have willingly gone deep into coding and design topics as an excuse to grow my skill set.
So I would propose the following as a litmus test if you're considering starting your own blog: if nobody read your blog would it still be worth it to you? I'm a sample size of one, so maybe this questions is unfair. Or maybe your situation is different and you have a captive audience ready to consume. But I hope my experience helps someone make the right choice :)