There always will be people for which the game is either too easy or too hard, no matter the difficulty setting. It doesn't make the game "unbalanced".
I do agree that it gets easier even on Death March as you level up, but it's still highly challenging enough for the crushing majority of players.
They won't, and don't have to make the game even more difficult to satisfy the whims of a tiny minority of players - and I'm one of these, as I love insane difficulties.
So I concur in what have been said : use mods. Period.
Alternatively, you can do what I used to do in other games to make them more challenging and realistic:
- Only manually save at "safe" places, such as inns, camps, villages and cities, and discard automatic saving (other than for recovering from game crashes or obvious bugs).
- Don't consume food or health potions in the middle of a fight. Because, seriously.
- Don't use perks giving you unrealistic boosts (such as the one giving you more health regen, for example).
- Limit yourself on what you're carrying, because having 5 swords and 3 sets of armors in your inventory just isn't realistic. It also means you'll indirectly earn less revenue by selling loot, making the equipment management and upgrade more complex.
- Any other similar tweak you can think of.
By mixing all this, the result is no more "fighting against all odds" bullshit, after a couple failures, you'll find yourself fleeing or avoiding deadly conflicts, as anyone with a brain and without a death wish would do (including a witcher), and learning to behave in a more well-thought way in your fights and wanderings.
I used to do that kind of things with games such as Stalker (with insane difficulty mods to make it even more challenging), and it's much more rewarding then, when your choices leads to greater consequences on the long haul: you tend to be more careful and realistic in your behaviours, as any misstep matters more, and you're more on a survival path than a uberpwning one.
It's a more rewarding and interesting type of difficulty in my opinion, much more than bluntly raising levels, hitpoints, damages and number of opponents.
Beside theatrical boss fights, fights that lasts minutes aren't realistic or challenging to me. I don't want to grind a healthbar. I want a meaningful feeling of risk and consequences.
I've been an Eve Online player for over 10 years, so maybe it affects the way I perceive the whole difficulty/risk/consequence issue.
But as a gamer for 25 years, it just makes sense to me. I've had my share of "hard-mode" games that just drops mountains of resistance and health to grind at. And it's nowhere interesting or challenging.