the original film was saved by Lucas getting a lot of input.
It’s called a writing process and putting hard work… of course you don’t reach perfection by writing first drafts that aren’t challenged. Something Lucas himself forgot when he wrote the PT: the core story was there but none of the hard reshape work was put into them. The gap between ANH and TPM lies there. Since at least Lucas is a wonderful storyteller there still is something appealing to those stories though : this is why the gap is also wide between TPM and OWK, this later being the low point of the saga in term of script where nothing is earned and no stakes are developed (I can’t still believe that Reva took Leia to interrogate her while Vader was fighting Ben: wasn’t her point to lure Vader into a trap so why the fuck is she doing that except for lazy screenwriters to remake ANH in the next episode ?).
and for TESB he turned to a very skilled writer.
And yet they drastically changed the first version of the script. Putting lots of work to make a worthy sequel rooted from ANH abs going into new directions.
You seem to discover that you get something of quality through hard work…