Miraculous as an allegory for entropy
The show can be philosophically interpreted as a metaphor for how people cope with the idea of death(/Destruction, as symbolized by Adrien). In the idealized sunscape that is Paris, reminders of Destruction (the fashion posters) are paradoxically everywhere yet unfamiliar to the children, who have not yet known loss personally. Their future roles as Miraculous vessels is also significant: the full pantheon of universal concepts is arrayed in that class, to which Destruction is new. Destruction is the newcomer, the stranger, the odd one out. It is no coincidence that Creation (as symbolized by Marinette) hated him at first sight. All the vessels see him as unusual (even Chloé, his friend, has a fundamentally different perspective than him), but Creation is especially alienated from him because he's so different to her. This antipathy is reflected by Gabriel, who only finds his son useful when he can be defanged and kept away from the world at large.Of course, hate does not tell the whole story. Marinette later loves Adrien, although traces of her initial fear remain in this love: she rarely talks to him and tracks his movements like prey. Adrien surmises correctly that she- for all her attempts at friendliness- does not feel comfortable around him. He is still not part of the group that Creation made and supports. Only when he masks his unhappiness, acts like a native inhabitant of Creation's realm, is he someone she treats fairly.
This duality appropriately shows Marinette's conflict over her heroic duty, that it is a noble calling yet there is a chance she could die. Her continued ventures as Ladybug bring her closer to Destruction and further away from everything she was familiar with. Ultimately, 'doing the right thing' where her realm is concerned means opening herself to newer things diminishing herself by accepting Destruction as a good thing since it made her a better person.
In that retrospect, Marinette's realization that there's such a thing as a 'good death', a Heroic Sacrifice for others preferred over being a life of fear and apathy, was something that Gabriel was unwilling to understand. Emilie and Nathalie figuratively understood Destruction's subjectivity and both placed others' well being before their own, each accepting the consequences of using a damaged Peacock Miraculous. Gabriel refused to follow their example, his inability to accept his loved ones dying poisoning his once noble intentions enough that he would kill hundreds if given the chance to bring them back. It's only when Gabriel finally obtained the Miraculouses, the power of Creation and Destruction, that he finally got their realization and literally embraces the ideal rather then use his acquired power for selfish gain.
