Serious.

For bond trading and analytics, often no one has the data other than Bloomberg. INTEX has a lot of MBS and ABS data, Trepp has CMBS data, and I guess there are some muni and corporate specialists, but Bloomberg has it all and at your fingertips with an ergonomic UX, and any analytics you can think of. If you want to actively trade fixed income, you just can't do it without a Bloomberg.

The previous post is valid. Other examples, corporate actions (up to date and historic), identifiers for instruments as they appear on particular secondary markets (eg, what is the name if this security on aquis europe), current and historic close prices (for any venue you could name), otc/si trade reports. The broad spread and generally high quality of data is what drives the platform.