There are two kinds of pleasurable feelings. The first one is a self-reinforcing loop, where the in-the-moment pleasure leads to craving for more pleasure, such as mindlessly scrolling through social media, or eating highly-processed, highly-palatable food. The second is pleasure gained through either thoughtfully consuming good content, like listening to good music or reading good books, or the fulfillment of a task that’s meaningful, such as getting good grades or getting a promotion for sustained conscientious effort.
The first is pleasure for its own sake, without any “real world rewards” that come with it, ie, distractions. The second isn’t as “addictive” as the first, nor does it cause the same spikes in pleasure, but it comes with real world tangible rewards.
There is no way to completely eliminate the human need for the first pleasure. But the need can be reduced. The ratio of second:first pleasure, is the degree to which a person is able to achieve his goals, the degree to which a person is successful.
How would “within reach” be defined? One of the themes of HPMOR is Harry using the scientific method to come up with solutions that the non-scientific wizarding crowd haven’t came up with. If the Laws of Thermodynamics can be transgressed in this world, solving death might not be that far-fetched of an idea.