You haven't done enough research
Houseplants might have some similar characteristics but they're not exactly the same. They need to be watered using different techniques because they thrive in different conditions and generally, they need to be handled the correct way depending on the specific species.
If you don't research properly and assume that they're all the same, they will keep expiring prematurely. Take your time to know about the indoor plant you have and how it needs to be taken care of.
The soil isn't right
Lastly, make sure that the soil you're using is suitable. Maybe you've been collecting soil from your backyard which most of the time, isn't the best for indoor plants.
It would help to buy soil that can supply nutrients that your plants need for them to survive.