I’m not sure that building is completely pointless now but at the same time, I don’t think it is the point of the game anymore.
With over 600 hours play time, it is by far my favourite thing to do. Before A17, by day 7, I always made sure I had a cobblestone tower set up with, if I’d been lucky to find / make a working forge, iron bars to stand on around the edge. By day 14, extend it a little, maybe putting some traps around it to slow down the Z’s. Then spend the next week gathering the resources to either extend the base out or start something stronger, giving more space between me and the ever increasing in strength and quantity Z’s. Over time, add turrets / blade traps to keep up with the increase in cops and radiated enemies. And repeat this as my game stage climbed ever higher.
Yes, in between there would be time to go and loot some POI’s and trade all that lovely extra loot dropped from your horde night success, and farm food and water and everything needed to survive in what was once a survival game.
Now, the game seems to be, go to a trader, get a quest, complete the quest, get XP and some reward and repeat.
Building a base in A18, because of the super intelligent Z’s on horde night who know where the weak points are, you effectively have to let them in on a clear path to you (same when digging underground) with minimal defences in between you and them and take them out. Or, trick the AI pathing by having a step they can’t jump across and watch them fall, run around and climb up again.
It’s rather a shame.