I do think for long-term viability, they need to vary the goals in each era. I mean, frankly, each civ has so many customizations, making sure each civ has one goal in their era which they make unique only makes sense to have as well. Like give Bulgaria one military point for every 20 tiles they pillage. Maybe don't have the Inca get points in distant lands, but give them points instead for cities captured or settled next to a mountain.
Another option, make the conditions way harder, and but give a second counter for each of the conditions. So in the ancient era, maybe instead of 7 wonders, your goal is 12 points, where you get one point for each wonder, and one point for each settlement with at least 5 quarters, for example (or like one point for each social policy slot you have unlocked). Instead of 20 resources, it's 40 total points, where you get one for each resource and 2 for each trade route.
Or, the final option, have a few distinct paths you can choose from, and a set point in the era, you pick which one you want. So maybe Ancient Era science you have 2 options for goals - one option is display 10 codices, another option is to slot 10 specialists into your cities, and when you discover Writing, you choose which of the 2 paths you want. That way, you have a potential choice in which direction you want to take your empire.
It would be nice if I could ignore the distant lands maybe every 3rd or 4th game, without basically sacrificing 2 victory paths. Let me choose which games I want to worry about religion in. That alone would probably double up how much you can play a sandbox game without being too forced down a path.