Just watched your video. If you had the top end apart, then your missing something simple...

Your timing belt is off (the marks can be deceiving, check and rotate the engine by hand 1 full rotation and see if they line back up??)

The bottom crank sensor is wonky, didn't get plugged in.

3rd.. Your plug wires! this is the most common!! Again, if you have NO CODES, no engine light... then it's probably none of the above.... and it's your coils/wire combination.

That video is short but it seems almost like no fuel. I don't see the motor bucking or trying to start like a mis-fire which seems like a crank sensor or timing belt issue.

What happens if you spray some starting fluid into the intake while someone is cranking?

Does it startup for a bit??

On my 3.5-SR... I had it apart 3 times..

1st time it sucked the bolt from the variable vane intake bullshit system into the heads.. Needed a head job (and I had the same problem as you.. IT WAS TIMING!!! damn belt! (120k miles)

2nd time.. Oil leak on the front seal! new everything up front.. no start like your but it was bucking.. sparkplugs/ coils were all mis-arranged. (190k miles)

3rd time. Got a valve seal leak and put ALL NEW top end stuff at like 260k miles. Injectors were plugged in wrong. That was fun!

Sold him (Lucky) after going all EV...

Point is.. it's usually something stupid and simple.

Keep it up with the videos!