[2022] What to do? Looking for objectives

Bases can get more elaborate with more complex trim shapes, windows, painting, garage and/or helipad, rooms with nice furniture, better lighting, etc. Since you want to focus on the practical, though, I like to take on major engineering projects in the world. Look at the map and your most visited sites. Is there a river or crevice that would be easier to cross with a bridge? Is there a hitch in the road you always trip over? Would a tunnel through a mountain cut your travel time to a trader? Would it be convenient to make a satellite base for processing loot in the middle of a city, so you don't have to go back to your main base after every mission?

You could also plant a big forest, and later harvest the wood to use it or sell it, if you don't want to get into farming proper. I assume since you have a "decent base," you've already explored mining.