I think the answer is:
People say unity is beautiful, I dare to disagree.
Electrons move on from atom to atom when a potential difference (voltage) is present, at least in metals (I'm not an expert)
I've had an impact on many products and artists.
Electrical products (technology) and artists (using modern tools on computers) which replaced older primitive equivalents
It upsets me that some human beings cannot see me some of my components.
Electricity itself (i.e stored charge, say) is invisible, as well as a lot of its components; under load, for example, producing heat which is invisible
I mark the end of difficult and tenacious times.
Electricity is regarded as essential for basic wellbeing in modern times (lighting, heating, etc.)
Yet people want to find my end, I always wonder why.
Development of more efficient sources of transportation and storage, sustainable production, and so on