Idk where you got this from, but Ukraine won in Kyiv, Kherson and Kharkiv. Currently the front moves very slowly towards Russia. No, the offensive isn‘t a huge success and I would even consider it a failure, but the fact that Ukraine can even start an offensive is proving that the weapon deliveries are working.
I wouldn’t call it anything yet, Ukrainians haven’t even used the bulk of their fresh troops and equipment.
No doubt it’s complicated, but some key factors are
- Availability of ammunition (cluster munitions may help here)
- Destroying artillery before advancing (the daily numbers have been looking good)
- Removing mines before advancing
- Disabling logistics (e.g. strikes on bridges, warehouses)
- Waiting for a lucky opportunity
It doesn’t cost them much to do things slowly, but keeping the Kremlin on its toes and embarrassed is good. The longer Ukraine holds on, the more equipment they get, like F-16s, Abrams, and ATACMS.