Well the Death of Captain Marvel was a touching tale, however it was a catharsis for Starlin to write it due to his father, and it was also part of the business deal so that he could work on Epic Illustrated and give us Dreadstar.
Any similarities between Dreadstar/Mar-Vell, Syzygy Darklock/Adam Warlock and Thanos/Lord Papal is purely coincidental of course
However, I digress. DoCM was also written in such a way that Marv had no choice but to die despite the fact that were some ways they could have saved him.
1. Titan super science can create new bodies, this was shown back when ISAAC computer was operating under Thanos legacy programs and created Elysius and other agents. So why didn't they clone a new, healthy body for him and transfer his mind/spirit?
2. A golden apple of asgard has healing and curative properties
3. Suspended animation until he is cured.
4. The Watcher: if anyone knew of a cure it would have been him.
5. Kronos the "God" of Titan that created Drax the Destroyer by putting the spirit of earthman ARthur Douglas into an artificial, cosmically empowered form to hunt and kill Thanos. He could have made a new body for Mar_vell and transferred him into it, if not actually cured him
Instead he dies and Marvel is stuck with a Trademark and no character to use it, then they make the overamped Monica Rambeau as the new CM until they realized she was too powerful and depowered her a lot for a time.
Then came Genis, son of Mar-Vell and soon he is made into a near copy of his father in terms of costume and powers and linked to Rick Jones. Then came editorial mandate and he is dead.
Phyla was never going to be CM and when she declared she was CM, Thanos scoffed at her.
Then Carol meets a Phoenix revived Mar-Vell and after he throws his new life away to save his people she takes the name in honor of him and their unrequited sexual tension/love.
In fact instead of Jean Grey always being the Phoenix, Mar-Vell would make a better host.