I agree, the first Thor film, I believe, it was directly influenced by JMS's run where Thor was supremely godly.
Unfortunately, the MCU learned a bit too late what to do with Thor; they realized they couldn't keep him OP because it would negate the rest of the heroes similarly to the comics.
In Thor's solo series he is usually depicted as very capable, but in team books he tends to be portrayed underpowered or the rest of the heroes are portrayed as more powerful then usual (which of course leads to the same conclusion).
I really wish JMS's run went on a bit longer and wasn't cut short by editorial mandate, I would have loved to see the godly version of Thor interact more with the rest of the Marvel Universe.
Thor basically has the same problem as Superman, their power fluctuates depending on the situation.
Similarly to what JohnnyMorales stated above, it can happen with the same writer, you have Thor swimming through the sun at one moment and in another moment he is being held down by frost giants and he gets his arm chopped off.
We just saw the Punisher kill a number of frost giants, a human man killing frost giants.
*PS: I wonder why didn't Unworthy Thor call down lighting to save him*