DND_Reborn
The High Aldwin
This is a good point. I like to explain it in a similar way:I think one of the things that is attractive in the simple, minimalist design around character advancement is that the acquisition of class abilities is not the primary motivation. The things the characters can acquire in the world, from wealth and magic items to land and social status, is much more important. This in turn produces more realistic and worthwhile motivations for the PCs, IMO. And PCs with strong motivations tend to be more self propelled, making the job of the DM easier in that you don't have to create reasons to compel the PCs to engage with the adventure. It is built in and if sufficiently developed you don't have to prepare an adventure at sll, you just have to adjudicate the consequences of their actions.
5E (as the most popular and recent edition) often seems to me about characters getting more features or things they can do (feats, etc.). This is represented by the fact that nearly every level gives the PCs sometime more than just hit points. Look at the class features in the class tables. Non-casters gain something every single level, half-casters most levels, and casters are the most sparse, but their feature-less levels correspond to gaining new spell levels as compensation. Now, this is of course, by design. It is meant to make the player feel rewarded for gaining each level. But IME it backfires--the focus becomes about gaining the level, not the adventure.
In B/X, BECMI, and even AD&D 1E/2E, you could often gain a level where the only thing you improved was your hit points. Gaining a level where your saves, combat table (or THAC0), etc. improved also was exciting! So, because the game was not as focused on gaining features, but instead on wealth, magic items, and other more "worldly" acquisitions, finding and completing the adventure was more the focus.
In short: 5E is about what you can do, earlier editions were more about what you actually did.