We didn't need the "niches" of already existing items to be emphasized, they were good as they were.

A few small stay adjustemnts to a few items would have been better, but changing randuins to only be good against crit and sunfire to only be good against minions, makes them unviable to buy.

You need the health from other items so much, and gargoyle stoneplate is mandatory now, meaning you would have to pick this up as a 4th item, but by then you STILL don't have enough health, so buying 350 hp isn't a viable choice. As a 5th item you STILL can't buy it because it doesn't provide enough stats to keep you tanky anyway.

Sunfire does the job of a mana item in a tanks kit and had a benefit of adding to trades, but now doesn't add to trades any significant amount. It's stats are matched by those of dead mans plate which provides a good passive instead, so it becomes an unviable purchase.

Tank itemization was good to begin with. Many items had niches to fill, and the only reason they wouldn't be filled is because we didn't have enough power in other items. Now our diversity is SHIT as health essentially isn't on items anymore, and we just pick the items that give the most hp, as the hp is worth more than any VERY SPECIFIC type of tackiness VS ONE PERSON.

Tl;dr, randuins and sunfire changes are shit and they didn't even need to happen really. Small changes sure, but these are way too far.