Tactically pretty interesting - even if they fail or aren't that serious about this, it forces Google to scramble energy and resources into defending their turf. Attention spent defending is attention not spent elsewhere.
what turf, Chromium is already open, powering Edge, and there have been rumblings that the DoJ could force Google to divest of Chromium anyway
Manifest V3 nonsense aside, I don't see at all how Google has a moat just because of the C++ one uses to parse html