CGPDFService high CPU usage on macOS Tahoe

What CGPDFService is

CGPDFService is a Core Graphics background service used by macOS to:

1 - Render PDFs (Quick Look, Preview, Finder thumbnails)

2 - Print PDFs or convert documents to PDF

3 -Display PDFs in apps like Safari, Mail, Notes, Books, and third-party apps

High CPU usually means something is repeatedly trying (and failing) to render a PDF.

Use the Activity Monitor application and select View >> View All Processes. Identify the processes using the most CPU and memory. 

Often, it’s a combination of processes. 

When the computer uses a lot of CPU and Memory, it may indicate a lack of empty space on the drive. 

In this case, the CPU and memory usage increase as the system searches for empty space to save changes. 

View memory usage in Activity Monitor on Mac - Apple Support

Indexing, post an upGrade, can take time

Depending on the about of changes that occurred between Sequoia and Tahoe and the amount of data even longer

But PDF files that Trae stored on the internal Drive and Not used in Quick View, Preview or some other PDF viewer application should not invoke the CGPDFService