Are the Necromancer's Golems of any use whatsoever in Diablo 2?

The Clay Golem is useful, as it slows down the attacker which allows you to interrupt their abilities (especially useful against bosses). You mentioned this yourself.

All it takes is one point. Resummoning is cheap, so there is no need to buff its health. Besides, +summoning skills will bring it acceptable levels anyway.

The cheap resummoning is also nice against bosses, as it allows you to summon an endless stream of new targets. Just buy enough mana potions beforehand.

So my advice: just invest that one point and resummon it when required.

Higher golems are not worth it. They die too quickly against bosses and don't do enough damage against normal mobs.

However, revived monsters are also useful in some cases. Again, just 1 point is enough as +summoning skill items will bring it to acceptable levels. And 1 point in all prerequisites, of course (I believe this includes some of the golems).

Around level 80, you'll have run out of other places to spend your points anyway.

I'm very surprised no one has talked about the hidden features of Iron Golem. If you have enough to invest in a (metal) weapon/armor with decent attributes or runewords, the golem will inherit most of the attributes (very useful especially for runewords that give auras such as Insight).

The only real downside with Iron Golem is that you lose the armor/weapon you use to make it. It won't disappear when you log out,unlike the other golems. The Iron Golem even becomes ethereal if you use an ethereal item to create it.

Stacking Summon Resist (helps buff your skellies too) and Golem Mastery can help to keep your golem alive against bosses and mobs later on in the game (at the higher difficulties).

If you have time and money to invest in your Necromancer (+summon GCs, gear, etc), you can equip yourself with Beast (or Faith, if you want to forgo an offhand), an Act II Merc with Might with Infinity, and an Iron Golem made with an item with Pride or Insight (a very good and cheap runeword to start with), once you have you army (all the auras stack and will benefit your summons immensely) summoned you'll be nearly unstoppable!

If you can't afford a good runeword, any item with Crushing Blow can help a lot (especially against the Act bosses).

this will give you a little enlightment on how golems are useful in hardcore games

You can't kill Diablo on Hell difficulty in hardcore without a Clay Golem, this will be a pain in butt on killing Duriel too, and on Baal he will never have time to summon Image or cast spell if you have clay Golem on your side.

Clay Golem will act as an element of slow in your army of summons and this strategy need you have invest skeleton army to Max+iron maiden and clay Golem in your hand, while boss are slow to zero act per 5-6 sec you cast Iron Maiden on them so if they could attack by any chance they will damage themselves, stay back and be alert on re-casting iron maiden Or on dodging spells like Diablo flame and shock, because of slow effect you will clearly see them coming and you shall have the plenty of time to dodge them easily.

If you want to judge clay Golem vs any other, I have to say Clay Golem is the cheapest and easiest way you can use Golem.