If you mean the Brave Browser ad on the Debates page, that shows even if you have adblock because it's a site-enforced thing (but you can manually get it not to show).
It's in the bottom-right, not bottom-left, of a computer browser page and on smartphones it shows at the bottom or something.
I've added those "ads" there coz I do believe in what Brave has to offer, especially for the ordinary people that don't want to spend lots of time to set up their browser. So all in all, it's a great product. And obviously it's a referral link, so they give me their tokens if somebody actually starts using it. So it's a win-win, as far as I can see it.
Spyware is defined as software that enables a user to obtain covert information about another's computer activities by transmitting data covertly from their hard drive.
Adguard is not "software" since it is not something that is downloaded or utilizes the hard drive. It is a google chrome extension.