How can you know? We have no information from dead people other than their bodies decay and they never communicate again. At least, there is no scientific data to show they communicate.
So this might lead a sensible person to conclude that that’s what death is: the end of life, but not the start of anything else, other than decay of the body. The person is no longer around. The person no longer feels anything. The person no longer perceives or experiences anything. Death, as far as the former person is concerned, is nothing; not even an awareness of nothing.
Other people certainly do think something happens after death. They have visions of hell or heaven, but these are more likely the result of sleep paralysis than they are to be the result of experience of anything with an external reality. We can safely say that the probability of such an afterlife is nearly nil, but we can not rule it out entirely.
So, assuming death is nothing, clearly life is harder. No brainer. Hardly worth asking the question unless you are a believer of these kinds of fantasies. Or if you are trying to find out who is a believer of these kinds of fantasies.
Although, you could look at belief in an afterlife as a sort of proof that life is harder, anyway. Normally, people don’t think their fantasies reflect real life. However, if your real life contains a lot of trauma or abuse, it can be a good defense to retreat into a fantastic belief in your mind. That is a way of protecting yourself from the mental trauma of a very, very difficult life. Or even an ordinarily difficult life. And everyone has difficulties. So perhaps it isn’t surprising that so many find a comforting fantasy and promise themselves that their fantasy will come true, if not in life, than surely afterwards.