It’s also not at all clear to me that the Kherson offensive has failed. It’s pinned down a huge number of Russian troops West of the Dnieper - which has weakened Russian forces elsewhere in Ukraine. But also, they’ve clearly lost ground in Kherson and are in danger of being cut off and encircled. Unlike the Russians, the Ukrainians seem to take operational security somewhat seriously - and I wouldn’t put too much stock in Russian claims of massive Ukrainian casualties, which they have been making since day one of the offensive.
Kherson also has two “elite” divisions of the VDV and a Spetsnaz brigade. The Russians put a lot of their quality there. Which means of course that they cant be used elsewhere.
And for all we know the Kherson pocket will crack open tomorrow. This kind of pressure is cumulative.
It hasn't. It is doing what you described and more. The attrition of Russian troops, resources, and officers is ongoing. And at some point Kherson will fall to the Ukrainians.