well what i mean by reasonable is that processing power will be so great by then that brute forcing all combinations could be practical so i doubt text based passwords will even be used.
processing power doubles every year (approx.)
4 * 2 ^ 20
4,194,304 ghz on a high end consumer processor in 20 years if the trend continues (it has for 50 years)
10gflops for a 4ghz processor nowadays.
so thats about...
faster than the fastest supercomputer in existence today on a highend consumer pc.
that would make text based bruteforcing easy.
per this quote it actually increases faster
This ignores a number of trends which Moore's law does not take into account. For example, the clock cycle of processors increases along with the increase in the number of transistors per chip. This means that processor power grows faster than Moore's law.