How to Efficiently Load Large JSON Data into ObservableCollection in .NET MAUI?

I'm working on a .NET MAUI application where I need to load a large volume of data from a JSON file and add it to an ObservableCollection. Currently, the application becomes unresponsive during this operation, and the process is slow.

[ObservableProperty]private ObservableCollection<TaskMang> tasks;

private async Task LoadTasksFromExcel(){
var filepath = "C:\\Users\\USER\\Documents\\excel_to_json.json";

if (!File.Exists(filepath))
{
    return;
}

var stopwatch = new Stopwatch();
stopwatch.Start();

try
{
    var jsonString = await File.ReadAllTextAsync(filepath);
    var jsonDocument = JsonDocument.Parse(jsonString);
    var root = jsonDocument.RootElement;

    if (root.TryGetProperty("Task_Master", out JsonElement taskArray))
    {
        // Use IEnumerable for lazy loading
        var tasksEnumerable = taskArray.EnumerateArray().Select(task => new TaskMang
        {
            id = task.GetProperty("TASK_ID").GetInt32(),
            TaskName = task.GetProperty("TASK_NAME").GetString(),
            TaskStartTime = task.GetProperty("START_TIME").GetString(),
            TaskEndTime = task.GetProperty("END_TIME").GetString(),
            TaskTimeTaken = task.GetProperty("TIME_TAKEN").GetString(),
            ProjectName = task.GetProperty("PROJECT_NAME").GetString(),
            SelectedProject = _projectDetailsViewModel.Projects
                .FirstOrDefault(p => p.ProjectName == task.GetProperty("PROJECT_NAME").GetString())
        }).ToList();

        // Add tasks to ObservableCollection in smaller batches
        const int batchSize = 100;
        for (int i = 0; i < tasksEnumerable.Count; i += batchSize)
        {
            var batch = tasksEnumerable.Skip(i).Take(batchSize).ToList();
            Application.Current.Dispatcher.Dispatch(() =>
            {
                foreach (var task in batch)
                {
                    Tasks.Add(task);
                }
            });

            await Task.Delay(10); // Small delay to prevent UI freeze
        }
    }
}
catch (Exception ex)
{
    Console.WriteLine($"Error: {ex.Message}");
}
finally
{
    stopwatch.Stop();
    Console.WriteLine($"Time taken: {stopwatch.ElapsedMilliseconds} ms");
}}

Performance: The application becomes unresponsive during data loading. UI Freezes: Even with batching and small delays, the UI still experiences freezing.

I tried : Batch Updates: Adding items in smaller batches with a delay. Lazy Loading: Using IEnumerable for processing data

Questions: Are there more efficient ways to handle large datasets in an ObservableCollection? Is there a better approach to avoid UI freezes when adding a large number of items? Any tips for optimizing JSON data processing in .NET MAUI?