The only thing I remember about the original Scorpion King where the scenes with Kelly Hu which were easily the best part of that movie IMO. Such a weak and forgettable film, but I understand why The Rock has a soft spot for it since it was his first real, leading movie role.
I was a huge fan of The Rock in the early 2000's too, but even I didn't care for that movie back then and while I do enjoy The Mummy Returns I always thought he was the worst part of that movie, especially that god awful CGI during the finale.
I will never understand how that spinoff happened when he barely did anything significant in The Mummy Returns, but it did and while it will probably never happen I would also rather watch a Mummy 4 with the old cast coming back than a Scorpion King reboot.