What you describe as "delay" is actually "failure". Go back and read the news reports, interviews etc from February-March - everyone ws saying that the aiom was to do a quick lightning strike with as much force as possible, to break through the Russian lines as quickly as possible and put Putin's troops into disarray.

Then to quickly take advantage of the surprise snd the Russian lack of coordination to cut the land bridge and retake Mariupol.

That was the plan. Then the fantasy crashed upon the reality of the Russian defences, the Russian air superiority, the Russian artillery superiority, etc.

Putin actually cares very much for Russian lives. That was why the did a strategic withdrawal from Kherson last fall. That is why they are hunkering down behind their defensive lines, killing Ukrainians at a 10/1 ratio.

One of Prigozhin's criticisms of Putin was that he was delaying the Russian advance, that he was reluctant to go on the offensive and mount attacks that would cost Russian lives.

Well, given what happened last week, there may be a change in Russian strategy in the offing.

Then you will see what a REAL offensive looks like.