Even though logic tells me the odds are staggeringly in favour of this being a simulation, my gut feeling is always going back and forth on the idea, so It feels more like the odds are 50/50. Maybe it's a case of lack of information. Maybe we don't know enough about the universe yet to make a call either way.
sidenote: You mention that more people are alive today than have lived in history. I've also heard this before but it isn't true. About 100 billion people have lived in total, and as you know the current world population is over 7 billion.