What is the need for using active low inputs like EN' (read as "Enable bar") in digital electronic circuits?
Almost fifty years ago, the dominant semiconductor technology was the (usually NPN) bipolar transistor, in the form of 74-series TTL logic.
This led to input stages that required some current to pull them low, and much less to pull them high - and conveniently, to output stages that were much better at pulling signals low, but could not pull signals high very effectively. (Study &quot;The TTL Data Book&quot; from Texas Instruments for more details)
And so, important signals like RD_n, EN_n, WR_n and RESET_n where the timings really mattered, worked better if you made them active low.
Every new design since then has remained compatible with this convention, so that they can be interconnected with existing devices, though with the advent of high speed CMOS logic, there is really no technological need.
So the reasons are compatibility (the way many CPUs have instruction sets still vaguely compatible with the 8086 from 1978) and engineers and worse, teachers, mainly familiar with the old convention.
A bit like the Space Shuttle booster size being linked to the width of a horse's butt in Roman times.