That's an insult to the intelligence of the Ukrainians who have been battling against Russian incursions for the past 10 years. Even Zelensky has been left frustrated by the "just wait bro" strategy of the west. Hoping for a complete Russian collapse and withdrawal at some undetermined point in the future is a recipe for disappointment. We can also look to the past as a good indicator for the future, and Russia has for better or worse always been very resilient in times of war.
On your point about insurgency; the whole Donbass conflict arose from pro-Russian insurgents in eastern Ukraine. Donetsk PR and Luhansk PR welcomed the Russian invasion with open arms. To date, the vast majority of insurgents in Ukraine have been on Russia's side.