Issue with icloud-please help

This is my last resort to turn to Reddit pros for help.

Long time user of Android, wife just got switched to iphone.

She had 15k photos and 28k messages which need to be transferred during transition. Move2ios just kept crashing. I followed reddit resolution for installing older version which worked for message but for photos, did not copy.

Now, sure it was not a big issue so i transferred photos from Android samsung s25 ultra, folder copy paste to windows and then the problem started.

Upon setting the ios, the icloud shows all 28k message which just does not get copied to message no matter whatever i do like toggling icloud message on off- selecting save to this device does nothing. This was around month ago.

Second problem, photos copy paste from windows takes iphone storage but does not show in gallery.

I then bought icloud+ and uploaded to icloud, all 15k photos got uploaded over 3 to 5 days but in iphone the photos were being downloaded like 500 a day. I am on nbn 1000/100 fttp internet and after around 7k photos, it stopped.

Now, i copied to external usb and then load it to iphone. Now, upon selecting save to iphone, it copies few and crashes

Then, i got google photos, uploaded all, then started copying like save to device from google photos, google photos had it organized monthly, after successfully copying few months then "something went wrong" message popped in google photos too

I rang apple support two times and both the time i got served by the most idiotic person i ever talked to. After explaining the whole thing, they ask if i am logged in, have you toggle the switch for icloud etc. so no success there too.

Now, my partner old phone had photos like burst photos and not sure if this is causing the issue but if someone could please give me some guidance that would be awesome as at this point i gave up.

Good, that i did not switch