re: When otherwise good movies jump the shark...

well like my earlier reference to TFA where the giant planet weapon and solo falling off the bridge down a giant tunnel with a reactor at the bottom exactly like the movie before it and the one before it.

that movie wasnt bad up until that point where you just think, "oh come on, this is the exact same scripted action as the last two movies" when had they just had solo fall on the ground was good enough and wouldnt have been a cheesy repeated scene, same with the death planet, there was no need for it and a simple extra large imperial cruiser would serve the same purpose. especially since they only had a handful of ships to fight it.

and the same cheesy design flaw of lets create a fully exposed self destruct thingy that a few ships can come blow it up and destroy everything

no need for much creative thinking, just have something new and different then a repeat of the last 3 movies as though its the same script with just different words and actors.

i really didnt like TLJ at all but at least it did try to NOT follow the same exact script of action as all the other movies.

with TLJ they pretty much killed the entire story line and plot so unless they do all the next movies in the form of a time before TLJ to fill in the blanks, then i think we see the first of the truly star wars movies bomb big time.