Well, I'm no longer a raw lad, but, speaking as someone who was only born in the 70s, let alone take up birding then, allow me to state that, in spite of the added distractions of the modern world, there are many very good birders who got in to the hobby in the 80s or 90s (and I'm not trying to blow my own trumpet, I'm on about really good birders, not adequate ones!), though, as yet, I concede that the old guard still hold the advantage.
Also, while out-and-out list-centric twitching isn't really conducive to increasing one's field abilities, it is certainly possible to approach twitching, at least in moderation, in such a way as to increase one's mental image of, and familiarity with, many species, such that it would be easier to claim the same species were an observer to find them at a later date. Heck, even people in Roker's top 20 have been known to twitch...!
While the younger generation may lack the real trailblazers of times past, I think it would not be too much of a disservice to say that, among those birders who are interested in ID matters, pay attention to calls etc, the general levels of knowledge today are greater than they would have been at least to the mid 70s. Now, I appreciate that a lot of this is a case of 'standing on the shoulders of giants', and I don't wish to be in any way disrespectful, but the average ID-oriented birder of today would no doubt cause quite a stir were they able to go back in time and show off their knowledge.
On a slightly different tangent, and speaking solely for myself here, I think that the learning curve never really ends: if one looks and listens hard enough, even so-called 'easy' IDs can be found, in reality, to be a lot tougher than they appear at face value: for example, a large gull with mid grey mantle, white head and bright yellow legs isn't necessarily a Yellow-legged, the really pale late autumn/winter Chiffchaffs aren't tristis, redpolls are a nightmare etc. The main thing is not to get disheartened by these challenges, and other more 'cutting edge' ones, but to enjoy the learning process for what it is, rather than as a necessary evil until gaining some sort of birding 'enlightenment'.
Of course, I don't always remind myself of this when I get bogged down over some 1st-w gull or other...
Regards,
Harry