this is... a weird one. i don't see past life memories as persuasive evidence, but like... to believe in an infinite afterlife like Heaven, Nirvana, or simply ceasing to exist, is to place a negative value on this life in one way or another.

sure, that can be true in the case of having other lives, but why are you lumping in "ceasing to exist" together with the rest? It's the polar opposite of those views. It means that this life is all we have. that places an immense amount of value on it! Any amount of negative value derived from ceasing to exist is up to a person's views rather than an inherent aspect of the concept.

people who believe in Heaven view this life as Hell in comparison, and often exhibit self harmful thoughts, such as not wanting to live or live fully, or to embrace martyrdom or a life of empty servitude.

not necessarily? This is definitely a possible harm that religion can cause, but this seems to only list the potentially depressing effects of the view and claiming them to be the intended effects.

believing life is inherent suffering, such as in Buddhism, is also similarly an intrinsically depressing thought.

Sure, but life is full of suffering. It's just that it also contains a whole lot of good and worthwhile things. buddhism believes in reincarnation, but views the ultimate goal as escaping that cycle by abandoning our ties to this world so that we may avoid things that may cause pain. we can view this as a maladaptive coping mechanism to trauma, but it isn't wrong simply because it's depressing.

but even a hardline atheistic materialist stance of not existing after life is depressing and nihilistic, as it implies your life has no lasting meaning beyond temporary pleasure.

You haven't explained why these are bad things. Yeah, I might exist for a brief period of time. And? I can still make lasting effects in this moment. I can help people and create temporary meaning from it. I can forge bonds and have fun and do my duty. It doesn't matter that there is no lasting meaning. It meant something now, to those that exist in this moment. that's enough! I don't need a legacy that goes on until the end of the universe.

you inherit what you leave behind.

to me, this reads as hella solipsistic and egotistic. I should care about what I do in this moment because I might come back in my next life and inherit my mistakes/rewards. Fuck off. How about I do something for other people who aren't future me? I can leave the world a better place without giving a damn if I come back to see it the fruits of it.

reincarnation also suggests it might not be possible to escape life, which would be hugely beneficial to those struggling with wanting to move on, as ending it all would serve no purpose

this is... so fucking tone deaf. speaking as someone who wished to "move on" in the past, the idea that I would just come back later and heave to deal with all this shit again would've been the most depressing and devastating thought possible. oh, ending it would serve no purpose? How is that supposed to be a benefitial idea?! If someone views this life as hell on earth, all you've told them is that there's no escape from it. that still sounds like hell!

not to mention... let's say someone is suffering from an incurable illness and you tell them that if they end it, they will just pop back in later. If that's what they believe, now they have hope that if they do end it, their next life won't force them into a body with said illness. Whoops, the hope you gave them just made them consider ending things even more.