What is bloat?

I'm thinking of doing a thing, and was hoping for some feedback (and maybe it'll change my mind):

1. How do you define bloat in a browser?
2. What are some examples of it, and what browsers have it?

So far I'm thinking bloat includes...

• Extra software that typically is standalone, like an email client or RSS reader
• Things that are not widely wanted in a browser, and could be extensions, like an AI toolbar or a cryptocurrency wallet
• Advertisements built directly into the browser

Are PDF readers bloat?How about LibreWolf's uBlock Origin?And why/why not?I've got some of my own reasoning in the list above, but I'm interested in others' thoughts.