This 100% -- the AI features already in Firefox, for the most part, rely on local models. (Right now there is translation and tab-grouping, IIRC.)
Local based AI features are great and I wish they were used more often, instead of just offloading everything to cloud services with questionable privacy.
If we look at the last AI features they implemented it doesn't like they are betting on local models anymore.
Local models are nice for keeping the initial prompt and inference off someone else's machine, but there is still the question of what the AI feature will do with data produced.
I don't expect a business to make or maintain a suite of local model features in a browser free to download without monetizing the feature somehow. If said monetization strategy might mean selling my data or having the local model bring in ads, for example, the value of a local model goes down significantly IMO.