Why is Zelensky still alive?
Because he has loyal people around him and also …

I have a different view on the assassination attempts. I doubt there was even a real assignation attempt by the Russians.
I am not saying that Russians were righteous gentlemen, they are vicious aggressors and no doubt about.
I think the reason why Russians did not really do any of it is that they need someone that can surrender to them. Just like when Americans did not take the emperor off during WW2. If Zelenskyy survives and is willing to surrender or come to an agreement with Russia, life after the war of Russia will be much easier. Zelenskyy is after all representing Ukraine officially. Sanctions may be lifted and Russians do not have to commit to more forces to govern and control Ukraine.
If Zelenskyy is assassinated, There will be nobody to negotiate with or even surrender to Russia on behalf of Ukraine. The country will fall into chaos and Russia has to commit to long and bitter warfare with different groups. They will be trapped in a similar situation as in Syria or Afghanistan. Russia will be badly crippled.
As for those claimed assassins, they may be some false claims by Zelenskyy’s circle to gain more sympathy or we’re done by somebody who wants to replace Zelenskyy.
After all, Russia does not need to assassinate Zelenskyy, they just need to use their terribly strong artillery to bomb Kyiv back to Stone Age. Don’t think Zelenskyy can survive that.
Just a disclaimer. I do not consent to Russia’s invasion no matter what are the reasons. I support the resistance of the Ukrainians. But I also support truth and unbiased news reports.