2014 Nissan Versa Note 1.6L 4 cylinder engine acc to google

I was told about 6 months ago that I need a new transmission and not to drive on the highway. Not wanting to put $6k into an older car, I opted to not get it repaired and just drive it until something else goes wrong and I am forced to buy a new car. (I hoped car prices would go down.)

The car was a little slow to start the other day, but I thought maybe it was the temperature drop. However, the next day when I was leaving work, the engine would not turn over. All the lights, windows, radio, touchscreen, etc worked just fine, but the engine wouldn’t start. For reasons not worth getting into, I couldn’t deal with it then so I just left it in my work lot. I attempted to start it the next day but now the engine didn’t sound like it was even attempting to turn over. All the other items worked still. I had told some people and asked if it just needed jump starting and a couple of them said that if all the other components worked on battery power, it was probably something else. Since I had previously decided not to put anymore money in the car, I didn’t have it towed to a mechanic and have been looking for a car to purchase. However, I just talked to a friend of a friend (who know cars more than the average person) yesterday who said that all those things could have worked and the battery just didn’t have enough juice to start the engine. I took a look at my car this morning and the battery is definitely dead now because nothing comes on now. Does this indicate it was a dying battery all along?

I don’t want to waste someone’s time trying to jump a worthless car, but I know you cannot tell me definitively. Could it just be a dead battery or are the “symptoms” more likely from something else? TIA