I can vouch for the overpoweredness of alchemy/smithing/enchanting in a combo. Already damning to the balance is getting only smithing and enchanting; alchemy is there just to overshoot whatever balance remains, but you could also just buy +smithing and +enchanting potions, though they'll not reach the same effectiveness later on (for a long time I found bought potions to actually be better).
Currently I can enchant 4 pieces of equipment to deal +35% damage with a certain type (one or two handed, or archery) and I think it maxes out at +40% damage each, so 160% damage total. Then of course you can enchant your weapon for an extra 20-30 damage per hit in elemental form. Combine that with the usual +damage you get from perks, and the upgraded damage you get from weapons upgraded to legendary, and things start to really get rolling. I've been using a bow, so I've also had the benefit of upgrading arrows every once in a while, as soon as level scaling brought enough of a new type available. And since I've also gone for alchemy, I can furthermore poison my arrows to deal an additional 60 or so of damage, or if I want to just murder whatever bits of balance are left, use a poison to outright paralyse an enemy for 30 seconds. If not I can just paralyse/poison again, or hell, use an invisibility potion that also buffs light armor and heals me, or whatever all the silly effects from some potions offer.
And, for archers, there then is the sneak attack option, first giving x2 damage, and with the right perk, x3. If I get the drop on a giant, I need about 3-4 arrows. Blood dragons go down just as quick. Just recently I've had ancient dragons or something like that spawn, and while they take a bit longer to go down, it's not as if they are a challenge.
So to get a challenge I've limited myself to only use a bow where I can't fight stuff off with a blade and shield. I used to have great trouble doing that, what with having no perks or enchantments focused on that play style, but after a while skills have started to get better, naturally, and now I'm again at a point where stuff starts to get easy on me again. Just for kicks I've murdered a few towns at the end of a session, at which point the enormous coterie of immortals, ranging from Jarls to random bums who for some reason are vital to story progression, starts to heavily kick in with their annoyance factor. Being on a murderous rampage becomes a lot less impressive if you accumulate with each step another member to your scowling entourage of immortal angry people, who however much you put them to their knees, again and again summon the courage to attempt to slay you hopelessly with daggers or fists. It would've been much more impressive, never mind satisfying, if said persons were to run off panicking rather than to resume their futile attempts.
Anyway, the further you go into crafting (ie. alchemy, smithing and enchanting) the further balance flees from your game. I've been playing on master difficulty since the start, and the game was very difficult and satisfying at some point, but after a tipping point around level 30-35 or so, I think it was, it only became easier and easier.
Edit: Just some quick numbers. I'm 'only' using an ebony bow right now, because I haven't found anything better yet. With my +dmg% gear on, one shot does about 200 damage, +30 fire damage, +24 arrow damage (tops that is, it's usually about +15, good arrows aren't thát plentiful). Add a +60 poison and you get a total of 314 damage. If only base attack damage (bow and arrow) is involved in the sneak attack damage, a x3 sneak attack does 762 damage. In comparison, the highest dmg dealing destruction spell does 150 damage, with, as far as I see, no good ways of upgrading it.
! Oh, and have Lydia or a similar follower equipped with the very best gear too. Or regenerating your whole lifebar with one easily craftable potion. Or near-complete resistance to all three elements with two potions. I have a friend that exploits the game (I don't play enough for that) and the amount of things that make it a walk in the park are astounding; at this point, my friend needs only summon said Dremora Lord for 95% of his fights, and to launch a few arrows for the remaining 5%. Anything getting close gets Fus-Ro-Dah'ed and ragdolls away. And he tells me it can become even more broken after you finish the main quest [spoiler:6008e39317] As you can summon a powerful Dragon and call forth the spirits of dead heroes, among other things [/spoiler:6008e39317]