Yeah, they are largely a historical artifact from before the days of equal-temperament tuning. A few things they have going for them:
* They give you a visual reference point for an absolute pitch. It's easy to find any specific note by looking for it relative to the unique pattern of black keys. C is always to the left of the pair of blacks. Other instruments require different techniques to keep track of where you are since otherwise all note positions look the same. (For example, guitars have fretboard markers and players have to be careful to count frets correctly.)
* Having two rows of notes, even if not evenly distributed, lets a hand span a greater range of pitches. If all of the black keys were inline with the whites, it would be harder to span an octave without making the keys smaller which increases the risk of mistakes.
* The non-uniform layout means that each diatonic key has a different physical layout. This is a negative when it comes to transposing, but it can be a positive when it comes to composing. Picking a different key with its unique layout might get your hands to try different chord voicings or progressions you wouldn't think of otherwise. It increases the spatial variet of the instrument at the expense of less consistency.
True. Honestly, from an engineering and UX standpoint, guitars are just breathtakingly brilliant. We don't give enough credit for how amazingly expressive, flexible, simple, and robust they are.
It's an analog instrument that you can make for a few hundred bucks out of a couple of pieces of wood and some wire. It lets play chords of up to six notes with one hand while articulating each note individually with great expressive control using the strumming hand. It allows a player to cover a huge range of chords across the entire chromatic spectrum and even supports bends and slides. At the same time, a beginning can make something that sounds nice within a couple of hours. It is simple to adapt it to electronics. And even when acoustic, it sounds great.
Learn how the black keys map to sharp and flat notes, then learn the cycle of fifths. (There are also some "tricks" you can use to understand how sharp and flat key signatures relate to their keys: in a "sharp" key signature, the last sharp sign matches the leading tone for the corresponding major key (e.g. G major only has F# as a key signature sign); in a "flat" key signature the last flat sign matches the fourth, and the next to last matches the actual key. F major has a single flat sign at Bb; Bb major has two, at Bb and Eb.) Once you have internalized how all of these relate, it really becomes trivial.
Sure, the steps are the same from the prime up, but with C major you end up on all white and with others you can end up on blacks here and there.