I think this most succinctly sums up my feelings as well.
While I disliked Short Round and Capshaw a great deal, the biggest issues were the suspension of disbelief that failed all the damn time. The unspeakable life raft scene has already been singled out, so no need to do it again, but the other big problem is that unlike 1 & 3, it had capital ‘M’ magic rather than isolated, relic specific and limited magic.
To clarify, in Raiders, the Ark had magic. But no one else did, it was all gee whiz ancient engineering and traps, which, while overblown, was well within the pulp setting and had at least some minimal believability. In last Crusade, again, no magic other than the Grail itself, plus more gee whiz ancient engineering.
In Temple, we have mind control magic, heart ripping / living heartless individuals (briefly), while the magic stones themselves only acted to burn the bag when Indy called out to them - if they have will, couldn’t they have figured out the evil high priest was unworthy rather than some bloody American with only a passing knowledge and connection to the culture?
Crystal Skull actually had potential, if they hadn’t been trying to shoehorn in ‘a worthy heir’ plot, although like everyone else I agree the fridge scene was amazingly stupid. I find the ancient aliens less objectionable than some, although it wouldn’t have been my first choice. Lots of other ideas had been bandied about, including some that ended up in other formats, or ended up as discarded drafts struck me as much more interesting.
Especially the treatment where Marion intruded Indy to their daughter. Because it would have been a great double-take moment where Indy could be forced to live up to some of his past actions towards women (his questionable early relationship with Marion and the casual flirting with female students).
So TLDR: Favorites in order are 3, 1, 2, 4, which I would rate as 9, 8, 5, 3. Temple is still watchable, but so deeply flawed I have zero desire to actively re-watch it. However, I wouldn’t change the channel if it came on, unlike Crystal Skull.