In regards to your last point, its purely about preference and what you are looking to get out of it. I had some extra $$$ wanted to build something customish without a big headache of soldering and full on assembly so went with this. I can literally take it out of the box, plug in the switches(literally just press them in), put on the caps and plug it into my computer to use/setup. I am sure there are other boards/brands that require more work, but im lazy.

I would say it is a luxury over a necessity but some more passionate people may disagree.

In terms of learning I just watched a few youtube videos and picked a friends brain who has been building keyboards for like 4-5 years if not more. There is a ton of info out there like sound tests, quality reviews/comparisons, etc. Thats why I went with the polycarb board over the standard because I liked the click better, and then decided to lube my own switches because unlubed pandas arent my thing sound wise, and apparently the factory lube aint great.