Thanks for taking the time to reply. I do use one of the last Intel Core i7 iMacs that Apple made... purchased in 2021. Currently running Sequoia 15.6.1. *(Just updated this week from 15.6 and this issue was happening on that version and I hoped that the latest upgrade would help, but didn't.) I also added 64GB (2 32GB Cards) to the two open ports thinking this may help... now a total of 96GB.
So, as you say I'm at the mercy of the Intel drive... but, all that I know is BEFORE upgrading both Pages and Numbers to the current 14.4 versions I DID see the dot on the icons in the dock and all existing files DID open normally.
*(The "dot" does appear on the icons in the dock when I click on them (when I click on the dock icons a "new blank file" opens immediately) and/or when I do "slowly" open an existing file the dot appears... but when the files are closed the dot disappears (The older versions of Pages and Numbers kept the dot showing when not in use.)
I have no anti-virus software. I do use Time Machine for backup... but connect the external drive used for this ONLY when doing a backup... not familiar with "Spotlight re-indexing"... so I doubt that I do this. Actually I never even use Spotlight for searching anything.
I've asked Apple Support techs if it is possible to go back to the previous version of these apps but they didn't think so.
Again, thank you for your time...and "if" this reply sparks another thought please share it with me.
Oh yes, one more thing I just thought about... "sometimes" (very rare, but like when the Apple support person is on the phone) the existing files open at normal speed. I've seen this occasionally and think... "it may be fixed!"... but, next time I go to open an existing file the 12 second delay occurs again. :0(