

From my understanding, Russia is running out of gas and their economy suffering significantly.
Ukraine is getting stronger and better defended. If they run out of money, they may be in some trouble, but that doesn’t seem to be looking likely anytime soon (large influx of EU money coming soon).
Ukraine can trade small amounts of land to allow Russia to grind its self down (Pyrrhic victory after Pyrrhic victory). Eventually Russia won’t be able to sustain their momentum and can be pushed back then (already seeing some evidence of this beginning).
Edit: spelling


“Stronger” is stronger than before, not stronger than Russia. Which would be correct multiple times a year over the past 4+ years.
Though at this point it does look like Ukraine is probably the “stronger” of the two. That doesn’t mean they are going to use that strength to grind back territory at significant loses. They care about their personnel much more than Russia.
No, Russia isn’t going to “run out” of personnel or materials. They are going to see decreased production that cannot match demand, which has already happened with multiple items. For example tanks, they have run out of T72Bs and have to pull the T72As out of long term storage. There are only ~1000 72As but it’ll last them maybe a year.
The articles about them producing hundreds of “new” tanks are presenting retrofitted hulls (like the T72A) as “new”. In actuality, they only produce a couple dozen modern tanks a year and they mostly hold those in reserve.
For manpower, they can crypto-mobilize “small” numbers of personnel a month, but they can’t mobilize the masses without creating unrest which would likely overthrow Putin (which is why they’ve only had the 1 mobilization early in the war). The crypto-mobilization has been able to exceed loses for most of the war. The last 5? months though, the loses exceed the number of new recruits.
Fossil Fuel sales fund a large amount of the Russian federal government budget. Even with the huge spike in oil prices due to the Iran war, Ukraine’s “kinetic” sanctions has seen Russia only be able to take advantage of a small amount of the windfall. They have reduced their exports to keep their population happy, which reduces their overall operating budget. Their budget has already peaked and is set to decrease each year for the next few years (in the middle of a war), because Russia’s economy can’t handle it.
Those “forever wars” you mention are not continuous kinetic wars, so I’m not sure they apply in this situation.
I agree when the end of the war comes is a political question, but each day brings Russia closer to the point where they are fed up with the war and want it to end by Ukrainian acceptable standards. Putin is unlikely to every give up, but if he ceases to exist, I expect Russian negotiations won’t be far behind.