Getting the experience advancement curve right on a game can (in my opinion) make or break a game. Some games use a very linear progression curve, or straight up linear curve (Fallout 76) and some use a steep exponential curve (Ever Quest). There are pros and cons to both approaches.
For me, I like a game to get harder, the further into it I get. This is an old school mentality of gaming that comes from years of games that literally get harder as you play (Zelda, Megaman, EQ, Final Fantasy, Ultima, etc.). Newer games (no, not all of them) often have a more forgiving experience progression (non-classic WoW, Skyrim, etc.). I can only pontificate as to the reasoning for this, and I hate to generalize about generation gaps, social demographics and various precedents set in other pop culture mediums that allow immediate and instant satisfaction to the lowest common denominator of effort. Putting our finger directly on the pulse of that topic would take a deep statistical study, well beyond my capacity.
Suffice it to say, generally speaking, games for me tend to fall into one of two camps: easy or hard.
For me, I have value to gain from both styles of gaming.
On the easy front, I enjoy that sense of growth and the rapid consumption of new content. Things stay fresh (hopefully), and I always log off with a sense of general (if temporary) accomplishment.
On the hard front, I get a longer deeper more permanent sense of accomplishment. Like anything in life, if you work hard at it, the rewards are often longer lasting and more emotionally significant.
So the question of which difficulty approach is best for any given player, comes down to the question of why we play games. For some they seek immediate entertainment, fast fun and a near spastic distraction from everyday life; these are the heroes of the moment. For others they seek a sense of sustainable accomplishment, deep emotional investment and a sense that they are just a part of a greater story. Then there are those who fall somewhere in the middle (which frankly will be most people).
Most games on the market right now follow a linear or near linear experience progression. This is partially due to gamer interest (as previously discussed) and partially due to business drivers and its need for companies to squeeze repetitive content to hold player interest for as long as possible (read: re-playability). Now, I am not talking about time sinks here (that is another horrid discussion), I am talking about the ability to make alts and re-level them to end game in a rapid manner, thus using the same content, to keep us engaged as we continue to pay. In short, if they had a steep leveling arc most players would not make alts and level them up, they would simply finish and move on to the next great game. Ultimately, it is more fun for everyone.
With that said… I crave the punishment. I sometimes want that steep exponential experience curve. I miss feeling like I really and truly earned something. I miss it, because for me, it was overcoming that challenge that gave the effort meaning. Those old-school games that made me try, made me think, made me angry, uncomfortable, and truly challenged… they also gave me deep emotional satisfaction. Alas these games are far and few between these days (mainly for the reasons given above): they are not as immediately enjoyable to pay; they require a much more cooperative and strategic game play style; and they rely on large chunks of widely dispersed content as opposed to a constant influx of new mini games (which does not lend itself well to a constant flow of smaller monetary transactions).
Is the exponential exp curve a dying breed? Not likely, but they are slow to be born. Here’s looking forward to the next big grind! 
For more on this topic check out this Gamasutra blog reposting: http://www.gamasutra.com/blogs/PascalLuban/20181211/332597/Quantitative_design__How_to_define_XP_thresholds.php