But it seems to me that many many Ukranian citizens are actively fighting to ensure their survival and the survival of their nation

You have outdated info. It might have been somewhat correct 2 years ago, when there were some volunteers. Now - it’s pure propaganda spread by Zelensky and parroted by the western media. Now, the only thing people do “actively” is trying to avoid being kidnapped on the streets or trying to flee the mass prison that is Ukraine, some dying in the rivers/mountains trying to do so.

And even those who fight - they don’t fight for their survival, not even for the survival of the state (although I guess in some sense you can say that), just for some peace of land, which the state wants to control.

If you don’t want to fight, that’s fine. Don’t fight.

Oh really? Thank god I have a choice. Oh right, I don’t - Zelensky’s regime will happily kidnap me, my family and my friends and send everyone to die at the first opportunity they get (although with me it will be harder, because I escaped Ukraine before the war started).

There should be no duty to fight

Indeed, I’m glad that we can at least agree on this.
If only you also stopped supporting those who force this “duty” on others…

but if you love your country

How can I love a country that wants me dead?

and want your way of life to continue, you should fight against the invading forces who want to destroy your country and way of life.

You are (most likely) looking at this from a perspective of a westerner, who has never been in Ukraine and/or Russia. If you live in USA, EU, or basically any other “first world country” - I can see why you would fight Russia to “keep your way of life”. Look at any metric you want (GDP, HDI, corruption, journalist freedom, amount of wooden toilets in the countryside) and you will see that both countries are the same shithole give or take. Average Joe wouldn’t even notice his government has changed.