I'm currently playing as Karaman for the achievement (which requires the Ottomans to not exist), and I agree that they are a tough enemy - but that's the challenge!
I had to ally everyone who might possibly help (Russia, Austria, Mamluks, Ajam, Tunis), build their trust to 100 (so they don't break the alliance due to wanting my land), incidentally get the "Trustworthy" achievement, and keep calling them to war for well over a century. I tried attacking the Ottos while they were in separate wars with Europeans, but had to do an emergency peace when they won all the other wars and multiple doomstacks started heading my way. At the same time, I had to grow somehow, and the only possible direction was east. Worse, while I nibbled on Anatolia, the Ottos were blobbing hard in the Balkans - for a long time, all I was doing was shifting them westwards towards the HRE. It's currently ~1630 and the Ottos are finally down to two provinces (including a very juicy 30-dev Kosovo).
Was this as fast and efficient as a true EU4 expert? No. Was it challenging and fun? Yes. Is the game better for having the Ottos as an endgame boss? Yes.
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EDIT:
Incoming obligatory "Ottomans are not impossible to beat, therefore its all fine


" comments.
Oops lol