Issues with memory stream or File saving potentially affecting performance?

Hello all I am working on a project where I am saving and storing a lot of to mobile devices. roughly 10 megabytes of of JSON Data converted to a string and stored in player prefs and converting a float array to bytes data and storing those bytes in a directory in the persistent data path .

I have checked and re-checked my code and all the lists and objects we are using to store and track the data are being de-allocated yet whenever we write the audio bytes to our memory stream we gradually see performance drops.

the amount of data isn't even the problem , it takes 6 save attempts before the performance drops so far that the project is basically paused . and this rung true for 6 5 second playbacks the same it did for 6 1 minute playbacks .

I just wanted to know if anyone who has done something similar has seen such performance drops and if there are any known ways to rectify the issue ? below is some code of my save process as it is now .

string audioClipName ="Slot"+pslot.ToString()+ "clip" + L.ToString(); string filePath = "";

         if(Application.platform == RuntimePlatform.OSXEditor || Application.platform == RuntimePlatform.OSXPlayer || Application.platform == RuntimePlatform.WindowsEditor || Application.platform == RuntimePlatform.WindowsPlayer)
         {
             //*** Here we create a file path based on combining our file name with our data path
             filePath = Path.Combine(Application.dataPath ,audioClipName);
             
             // if this file exists , we read the existing bytes 
             if(File.Exists(filePath)){
                 //*** we remove pre-existing data
                  System.IO.File.Delete(filePath);
                 
             }
             //else if unity is currently on an iphone or android device  , load bytes from the persistent data path 
         }else if(Application.platform == RuntimePlatform.IPhonePlayer || Application.platform == RuntimePlatform.Android){
             
             //*** Here we create a file path based on combining our file name with our data path
             filePath = Path.Combine(Application.persistentDataPath ,audioClipName);
             
             // if this file exists , we read the existing bytes 
             if(File.Exists(filePath)){
                 //*** we remove pre-existing data
                  System.IO.File.Delete(filePath);
                 
             }
         }

         //yield return new WaitForEndOfFrame();

     bytes = ConvertFloatsToBytes(audioFloatData);

         DebugTools.Log(" converting bytes to float ");
     yield return new WaitForEndOfFrame();
         
     System.IO.File.WriteAllBytes(filePath,bytes);
         DebugTools.Log(" Saved bytes ");

We use the yield statements to give a brief pause in between actions, we thought running intensive process immediately after intensive process was possibly making the save flow even more processor intensive than it had to be .

I nearly included the playerprefs save functionality but I honestly don't think that's where the performance drop is coming from . I haven't done much save functionality so any and all advice or resources are appreciated.