I'm a level 21 warrior, my blacksmithing and enchanting are both around 50, my heavy armor, one handed weapon and shield skills are in the 40's and my destruction, restoration and conjuration (and somehow speech and lockpicking) skills are in the 30's. I'm probably a good example of a jack of all trades character and the game IS difficult at times but with my great smithing I was able to create exquisite steel plate armor for myself and lydia (enchanted with health bonuses) and an orcish shield for myself (shield enchantments) as well as fully upgraded elven weapons with 15 fire damage.
I pretty much destroy anything that comes in my path, though some silver hand bosses and dragon fights do get the better of me but I've never once met an unbeatable boss. Sure if I exclusively levelled my block, heavy armor and one handed till I was level 20 I'd be able to kill the bandit chief in 5 hits instead of 20, but the fact of the matter is that I didnt. Instead I have great armor and weapons and a whole lot of money I dont know how to spend, Its all about balance. If you fight alot, expect to be a good fighter and do even more fighting. if you craft alot, expect to be able to craft even better things and make a whole lot of money. Game's going great for me so far
Yea well the funny thing is that you can only see that when having 2 characters. If you had not leveled up these skills your character would be more powerful. If you don't believe me, test it yourself.
Ah and btw i got steel plate armor at around level 15 with my warrior from dungeons.
After realising this thing you will see that non-combat skills gimp your character except maybe when "you powerlevel a skill like enchanting to 100 and doing all the enchantments right away" since enchanting is op. But this obviously svcks. This though is the only way "you will feel progression" if you waste your time with non-combat skills.
It's funny how people say blacksmithing etc are great. It will seem like that since they don't have a character without them to compare them to and since they already gimped their character while raising it, when at 100 they felt an upgrade and just simplisticaly thought "ah blacksmithing or alchemy or etc is good".
For example they make a bunch of potions with alchemy etc but the really funny thing is that if they didn't have it in the first place they would not need these potions/weapons/etc at all!