ngl.... if i was a royal i wouldn't fight for the throne lol that shit looks so tiring , i...

but the princess here did become a marchioness but her husband died and now since shes no longer useful to the crown prince she ganna kill him just like mc's last life

i think most fight for the throne because not fighting for it likely means dying by the hands of the one that succeeds. (those who don't help are my enemy kind of shit mindset)
those fantasy royal families are very cruel.
if you are strong enough and can run away, that would be the best. but not everyone is as fortunate as MC and ML.

True, it depends on the sort of royal family you're born into （/TДT)/
might just have to fight for survival

exactly, i also thought that phrase was a bit too absolute, and that is why i included the "fantasy" word. i think the more power is in the hand of individuals the more we see those very cruel outcomes (since they don't need to appease armies and keep a public figure). not like it doesn't happens with "normal" worlds, but on those the competition seems to be more toned down, since everyone is a normie and part of leading is convincing a lot of people (you can't brute force everyone)...
now with worlds with magic and such... oh shit... once one of the princes has/is the strongest one, the others need to run for their lives.
i don't think this world in particular is nice either, since past life we saw the sister getting killed in public. it is clear the competition is fierce.
well... that also explain why those empire fall so easily, since they are always killing talents that don't act like slaves.
i mean, even including all that, leaving and living away from this shitshow is much better tho. fighting with their lives in the line to serve others? better to stay away and make money with their talent. unfortunately, when one is fed ambition since the beginning, the preaching becomes chains... they can't see anything else but that one objective that was fed into them.