Here’s why:
1) It makes it very easy to update your web presence - easy is good because easy gets done
2) Locally you can use a blog to gain exposure that your competition can’t
3) Search engines love blogs (still) and will reward you with better search results when your prospects go looking
4) The daily and weekly choir (that may be how you initially view it) of producing written content will make you a much better communicator, marketer and salesperson - it’s the killer activity