Throughout history of our world, there has always been ways to end one’s own life, their loved ones and those of enemies in battle ..and during times of famine and pestilence.
The ‘immortal soul’ that has to meet the monotheistic maker changed everything because euthanasia means banishing saved souls to hell and hence becoming unsaved.
Edited to add: perhaps after spread of xianity. The Old Testament begins with a sacrifice after all. I am not terribly familiar with details re religions..correct me if I am wrong?