I think of size when I read bloat. A simple HTML content page deeply nested DIV-soup and 14MB of JS and 2MB of CSS: bloat.

Bloat is code size/ program size that is not actually needed.

Bloated code bases are usually harder to work on and may have noticeable slowness: but not necessarily! Maybe the bloat of aforementioned HTML page is due to the use of a low/no-code framework that makes it suuuuper easy to maintain. And with internet being fast these days, many user may not notice 15MB "bloat" (=unneeded size), as the page also loads a video and several high-res images making the total add up to 60MB+ before all bells and whistles are showing.

EDIT: typo "internet being fat these days" -> "internet being fast these days"