You might try also the CompressionQuality property, 60% instead of 90% should reduce the size in bytes (losing quality of course)
https://engineertips.wordpress.com/2021/11/27/delphi-resize-jpeg/
The Webp format is an alternative, it gets smaller size vs jpeg with the same quality, and there are Delphi libraries to do so in vcl (and fmx)
https://github.com/Wykerd/delphi-webp