The key parameters governing feasibility of human interstellar travel are the average human lifespan in years and typical interstellar distance in lightyears. These are roughly 72 years and 5 lightyears, respectively. So it takes about 70% of a human lifespan to travel a typical interstellar distance at 10% of the speed of light. This is... not great.
The key realization is that the relationship of these two numbers is in a sense an accident of biology and astronomy.
It is usually assumed that future technological progress might enable travel at a large fraction of the speed of light, but it is often missed that future medical progress might extend human lifespan to say 400 or 1000 years.
A scarier realization is that intelligent aliens might have natural lifespan that make interstellar travel seem far more practical.