So is Opera itself. Vivaldi has made more of an effort to have the same functionality and look/feel as the original Opera.

But it won't help if manifest V2 supporting code is finally deleted from Chromium.

Vivaldi already has a built-in adblocker in place, so Vivaldi ad-blocking doesn't depend on V2 being available.

This said, V2 shouldn't be removed at all because this will stifle the extension ecosystem. I predict that extensions will stagnate. Just because some ad-obsessed company killed V2 to stop an extension threatening their revenue.