Marcille is 50 at the start of the series, while Frieren is 1000+ (at a point where 50 is a rounding error). It probably becomes increasingly hard to connect the older they get.

I've seen a few settings and arguments that low lifespan creatures are more creative because they have a drive to improve their (shitty) situation and leave their mark to be remembered, while long lived races like high elves don't care about being remembered after millenia (because they will still be there lol) or improving things because current status quo is kinda great if you ask them.

Which is why I like how in Warhammer 40k humans are the race with the highest psyker potential, it's just that the average elf/eldar has the lifespan and psyker potential of an one-in-a-million gifted trained human psyker.

It is a testament that, in a setting where regular humans are still short lived and powerless, one such man grew to be the third, arguably secong strongest psyker and strongest baseline human who ever lived (Malcador), and his power enabled him to live for millenia. He certainly was much more active and creative than the your average elf during his time and certainly never ever said "I lived a full life, I did everything that could be done, I had a good run".

Malcador died as he lived: Getting shit done.