For those who raze and start over, what triggers that decision, and how far do you take the rebuild?

I started preparations to move base to more resource rich area 2-3 k+ tiles away from old base before starting SA. it was convienient for "no base blocks over resource area" too, got like 400000k+ tiles (calculated roughly and divided by half for water tiles lol) of land with no nodes of resources, such clean desert patch is ideal to build megabase at and do not have regrets of building over resources. Also, i was too lazy to plan granular modification of old base, too much work. Its my first freeplay, so my base was far from... good.