The speed of the reintegration process depends on the drive hosting the catalog and the drive(s) with the original image files. What type of drive(s) are you using? Are all of the drives with the images files connected? A local SSD drive hosting the catalog will have the best performance. A networked NAS volume hosting the catalog will be the slowest. If the image files are on an external SSD with USB C, Thunderbolt 3 or 4 interface, then the performance should be close to an internal SSD drive volume.
If your drive volumes are both using a slower interface, then your reported reported reintegration time is not longer than expected for the number of images in your catalog.
Best regards,
--Bob