GPLv3 makes a company publish the source under the same license. That means no Vivaldi, Chrome, Edge or any other spyware ad ridden browsers. I don’t think we need more lock in.
I understand your reasoning, but I think your logic is flawed. If Ladybird is GPLv3, then browsers will continue to use Chromium base which helps the Chrome monopoly. By making it BSD, it will help others adopt it.
We don’t need that much adoption we just need a engine that is capable of not screwing over everyone. We already have plenty of proprietary browsers.
Admittedly BSD may help Ladybug get more funding and development efforts.