Twitter's reach extends beyond it's membership. Tweets are public and rank highly in search results, so even if you have no followers, someone googling your name or keywords will often see your Twitter account on the first page of results.
Ease of use
The platform is simple to use and handles media well. When you link YouTube or other sites, Twitter previews and embeds the content automatically. Other platforms create barriers to prevent users from leaving their ecosystem.
Short form messaging
Working with Twitter's character limit will help you hone your communication. This skill will transfer to your SMS, email, and copy-writing style.
Posting regularly conveys to your audience that you are reliable, consistent and hard working. You are also demonstrating that you are engaging and switched on.
It's a great platform for testing different ideas. The ethereal feel of Twitter is forgiving in terms of using humour and trying things out.