VindictiveJudge

So as the year 1900 rolls around, I control 1/3 of the map landmass as territory under the work of my cities I cover the entirety of a large dorito shaped continent

However, one of the other human players has just researched nuclear theory and I’ve just figured out Great war infantry. I still have not caught up but I have made massive gains.

Well, there’s your problem. Civ 5 had a thing where research took more science points to complete the more cities you had. The ideal number of cities to own was five. If you had even a single city over that, even if science output was maxed out in all cities, it would take longer to research anything than for a player with only five cities.

Religion victories in Civ are poorly telegraphed in general. You can easily look at the minimap and see that someone is conquering everything, and poking at a player’s borders will show you that they’re technologically advanced, but religion and culture victories tend to sneak up on people.