A browser with current definition obviously doesn't "need" AI. And we also know all too well how it's going to turn out - they will both use the AI to push ads onto us and also collect and sell our personal data.

However, a strong locally-executed AI would have potential to vastly improve our experience of web! So much work is done in browsers could be enhanced or automated with custom agents. You'd no longer need any browser extensions (which are privacy nightmare when the ownership secretly changes hands). Your agents could browse local shops for personalized gifts or discounts, you could set up very complex watches on classified ads. You could work around any lacking features of any website or a combination of several websites, to get exactly what you seek and to filter out anything that is noise to you. You would be able to seamlessly communicate with the Polish internet subculture, or with Gen Alpha, all without feeling the physical pain. With an AGI-level AI maybe even the Reddit could be made usable again.

Of course this is all assuming that the web doesn't adapt to become even more closed and hostile.

If someone tries to sell you an AI browser, tell them I've got some pictures of apes to sell

Translation?

Image search?

Live captions?

Dubbing?

Summary?

Rewrite text better?

Technically, a browser is a “user agent”, and it could be argued that some AI features (with privacy) can help in being a better user agent.

A bored LLM that will constantly hit reload on hackernews hoping to see something new.

Comet, for one

It is really incredibly nice to be able to highlight a passage, right click on it, and select "Summarize" or "Explain this." That's all FireFox does at the moment. It's an option on the right-click menu. You can ignore it. If nobody told you the evil AI thingy was there, you would probably never notice it.

This is the equivalent of Blockbuster rejecting Netflix.