@Kevin Fillmore
The issue isn't about tridents despawning; it's about them falling through blocks when loading the chunk.
If you place a trident upon a block then reload the chunk a few times, you'll see what people mean.
Yea, this bug has been around for ages now with signs of remediation. The issue is not hard to reproduce, and no world file is required; this is a consistent bug that needs attention.
For me, the issue disappeared just over a month ago.
The OP mentioned chunk generation being a primary cause for degradation in performance. When I had this issue my server CPU would hit 100% with a single player flying around, now its ~5% :3
I know this kinda old, but im still having this issue.
Approx 2 updates ago performance was perfect, then it degraded after an update.
Now, with 1 player the server reaches 100% CPU utilization and the performance drop is especially noticeable when loading chunks (extremely slow).
SilentWhisperer, a popular Minecraft Bedrock YouTuber, even highlighted it as one of the most destructive bugs in a recent video.
https://youtu.be/Uju_ff-16Mo?t=747 (at 12:27)