its really a strain or burden on the system being "lifted" from Palestine since presumably that soldier does not have a day job and doesn't actually "produce" anything
your looking at it wrong.
A Hamas soldier brings money into Palestine, his salary is paid for by Iran.
He is providing for his family, bringing money into his nation, putting food on the table, putting money into his local economy.
He is not a burden to Palestine, he is a burden to Iran, and in an area controlled by Hamas, where the rules are set by Hamas, in a way he is for a time, an asset to his family. One of the few regular jobs to be had that pays "good" money in that area. A person who can make sure his family is not victimized by Hamas.
We might not like it, but it is an understandable choice. The fact he is terrorist does not change the fact he is a professional soldier that will be better trained and better prepared then the vast majority of what the IDF has to oppose him with. Yes, he has to die, but do not think for a second killing him will be remotely easy.