The problem is the pacing.
russia exhausted it's offensive potential in Feb. - Apr. 2022, rebuilt and exhausted itself again around Bakhmut and Avdiivka in Oct. 2022 - Mar. 2023. They're rebuilding again even if it's with T-55s. And again if needed. And again.
I've read a newspaper article that Ukraine has been having severe problems in recruitment since at least Jan. 2023 with the number of volunteers having dropped off significantly and trying to get unwilling draftees from where ever they can. The attrition ratio being so high that who ever signs up knows they're going to get severely injured or killed. Loss ratios among a lot of Ukrainian formations surpassing 100% since the start of the war.
Ukraine had one chance of a proper heavy offensive, the Kharkiv offensive was an opportunity that presented itself and was carried out by light forces against unprepared opposition. Kherson already showed that attacking prepared russian positions was going to be a grind. The problem is that the offensive has come a year too late. All of the equipment and more should have been sent in Feb. 2022, not Feb. 2023. Back when russia wasn't dug in properly behind huge minefields and with the few possible axis of attack well known to everyone. When they were still off-balance. When Ukraine had the units of the most motivated people still more or less intact. Instead the sending of new equipment has been at trickle rate. Every time trying to gauge whether or not Putin was going to nuke the world over a few redundant pieces of kit. The nuclear threats worked.
russia and Ukraine are trading blow for blow. Putin is right in going for a long war. The population disparity is almost 4-1. Ukraine won't be able to sustain this for long no matter how long the west can and wants to keep supplying them. The russian population will never given in no matter how many they lose or how bad things become in russia. Conventional theories of warfare don't apply to a population that prides itself on it's history of suffering.
In the end at best it will be a stalemate. The only way for Ukraine to win is to completely drive russia from it's territory and they simply lack the forces to do that. The only way for russia to then stop attacking Ukraine is for Ukraine to be admitted to NATO a week after kicking them out and we all know that won't happen either. Ukraine will be left open for another attack while western politicians discuss the democratic process and LGBTQ acceptance in Ukraine ad nauseum over the next 15 years.
There is no winning here, even if Putin dies his successor will continue the war or escalate with (tactical) nukes and/or a full mobilization. Putin solidified his status among the russian people as a leader in the same way, by beating up the Chechens. He just underestimated the "easy prey" at first and got a bloody nose for it. Any new leader will seek to do the same, with the target already having been selected by his predecessor and the tools in place.
Imo NATO has squandered the better part of a year and thereby the only realistic chance Ukraine had of winning the war.