Unlike Christ, our sources for Buddha are centuries after the fact. As a result, there's a wide, unbridgeable gap between the historical Buddha and the literary Buddha. We don't know what he really said and did. All we have are legendary or fictional traditions.
Also, because humans have an innate need to believe in something greater and better than themselves, Buddhists have essentially deified Buddha. He becomes a larger-than-life figure. A surrogate God.
However, lack of solid historical information about Buddha is inessential to Buddhism. Christianity is inseparable from the person and work of Christ. Even if Christ taught nothing distinctive, his uniquely redemptive death and unique person (as the Incarnate Son) make the medium inseparable from the message. Christ isn't just a roadmap, but the destination.
By contrast, what's significant about Buddhism is a set of ideas. It doesn't matter who said it. With Buddha, unlike Christ, you can detach the message from the messenger.
According to tradition, Buddha had a certain insight into the problem of evil, based on two related ideas. Life is fleeting. Everything changes. Nothing lasts.
Hence, if you become emotionally invested in something transitory, you leave yourself open to grief when it passes out of your life.
So the way to spare yourself that kind of suffering is to practice detachment. If you don't care about having it, you don't care about losing it.
Thus, Buddha offers both a simple diagnosis and simple solution to the problem.
There's an undeniable truth to his analysis, as far as it goes. It's a truism that the more you love something, you more you stand to lose if you lose it. And it's also true that given the evanescent nature of so much human experience, we are quite vulnerable to this type of suffering.
There are, however, some fundamental problems with his insight:
i) It's one-sided. Although impermanence can be a source of suffering, a static existence would be interminable. Humans need variety as well as continuity to be happy.
ii) Notice that on this view, the problem of evil is essentially metaphysical rather than moral. It's grounded in the impermanence of a timebound existence. An amoral analysis of the problem of evil.
As a result, a Samurai warrior can be pious Buddhist. Butcher innocent men, women, and children on the orders of the Shogun.
Although there's such a thing as Buddhist ethics, that's arbitrary. For the problem of evil isn't moral evil, but impermanence. And since humans are temporary organisms, why treat them with any particular deference?
iii) It's a this-worldly solution to a this-worldly problem. Because Buddha isn't God, he can't change the situation. He has to take the situation as a given. The best he can do is to propose a palliative. Given the situation, here's a bromide to make it feel a bit better.
The Buddhist worldview is essentially pessimistic and fatalistic. Defeatist. There's nothing you can do about your condition. That's beyond your control. At most, you can adjust your attitude. Come to terms with the situation. Make the best of a bad deal.
Given its bleak outlook on life, there's an ineluctable undertone of sadness to Buddhism. Our condition is unutterably hopeless. The best we can do is to numb the pain.
Buddha was just a man. A creature. A mortal. A passenger in the same sinking ship. He is impotent to change the condition that gives rise to suffering in the first place. If all is flux, then even if gods are powerless to change the fabric of reality.
This is completely unlike Christianity, where the ultimate source of suffering is due to sin rather than nature. And where the Savior has the divine power to change the situation.
iv) At best, Buddhism avoids one type of sadness by exchanging that for another type of sadness. There's a kind of sadness that comes from losing the good you had. But there's another kind of sadness that comes from missing the good you never had.
Both are deprivations. In Buddhism, you deny yourself a good to avoid grief when you lose it. But you still lose out in a different way. That good is still absent from your life. A felt absence.
What's worse: the absence of what you never had, or the absence of what you used to have? You can miss what you never had as acutely as what you lost.
v) The solution is unrealistic. Suppressing our emotional needs doesn't make them go away. Indeed, suppression tends to intensify the yearning.
And even if you could successfully suppress your innate emotional needs, that would be inhuman. That would make you less virtuous. Almost sociopathic.
Buddhism tries to skirt a knife-edge between happiness and unhappiness. But, again, that's unrealistic.