There are many more facets to Toastmasters than just public speaking. Toastmasters is continuing education to prepare for real life. Think beta test.
Toastmasters is a culture where learning by doing and failing is encouraged. Starting with the most obvious - public speaking - It is common practice to use one's club to hone an upcoming presentation. Although it's an intangible and I can't cite specifics, people who communicate the best are more successful. Ever since I joined Toastmasters, I read aloud any written communication to be sure it just sounds right.
The leadership track is a parallel track to the milestones of speaking. It teaches organization and management, mainly learning how to get members within one's club and other clubs to work together. The high performance leadership project is the culmination of the leadership track. Sort of like final exam for getting a black belt.
As a member progresses, he or she will become more adept at problem-solving. The pressure of the meeting deadline helps. Specifically, meetings with inadequate attendance forces members to improvise with "double duty" meeting roles. Any club will inevitably have to deal with the perennial "churn" issue and budgetary shortfalls. As a member progresses to leadership roles, the buck stops with them.
Here's an example: A "captive" club met at a business before regular office hours. There were many no-shows. They improvised. Two people called in sick for a presentation for a major client at 10 AM. They repeated the drill with two team members who were Toastmasters to take up the slack.
You can't beat the dreaded Table Topics exercise to prepare for a snap quiz from the big boss.
Tell us about an example of Toastmasters preparing you for the real world.