Zelensky dissolving this trilateral group bars the doors to a diplomatic solution of this conflict in the foreseeable future.

Putin can sit back and watch Ukraine bleed all its non-fascist, non-radicalized citizens to Europe sooner or later. For those wanting to migrate to Russian territory, he opened the doors. He already "won", so to say.

If US and its EU vassals aren't willing to risk a nuclear war, which I assume of course.

US and EU can ship as many weapons as they want because soon there will be nobody "sane" any more willing to wield them on Ukraine's end of this stick.