Yes I think the game gets too easy after you've reached 20+ levels. Master level before those levels seems really perfect difficulty to me. You have to think, use your enviroment to your advantage, make your NPC tank, etc. great stuff. And I am playing with a Nord with 2handed sword with restoration.
The real problem is the items and their effect stackking. You can make way too powerful items way too easily. Smithing and enchanting professions are just broken

I haven't tested playing without them yet (still using first char), so can't really tell if its issue even without those professions. But when you get to make your first dragon or even daedric armors, the game gets ridicilously easy.
My character is now level 42 and here are his stats with the equipments and lord stone (one of the guardian stone):
Magicka 240
Health 350
Stamina 400
Fire resistance 84%
Cold resistance 50%
Shock resistance 79%
Magick resistance 67%
50 points of damage resistance
2handed sword with 234+37+25 dmg (from gauntlets he even gets damage increase of 45% more damage)
Basicly I don't die to
anything. The items are made only by using smithing and enchanting and you can clearly see that those are way too good to be true. I can one hit 95% of my enemies and even dragons die to 4 hits and I take less than 10% damage loss from Elder dragon when fighting them. Giants die in two hits. I know that some people run here with their mouth full of froth and anger telling me that I should stop using those professions, but that's just really stupid opinion. Those professions just don't scale at all on higher levels and it needs to be fixed for them being enjoyable professions. Who really enjoys playing really really badly and using the same armors you found in first town just to convience themselves that the game difficulty is enough and some mechanics aren't plain broken? No one since thats just plain stupid!
I really really really would like to Bethesda fix master difficulty to be as hard on later levels as in start. The problem main problem is with way too high armor ratings on equipments and stackable effects. Well even without stacking you can get 42% fire resistance + 22% magick resistance, so it needs to be fixed soon. But that's just my two cents