The previous report was closed as "Works As Intended" because the assignee was under the impression that it has always worked that way stating, "This is a well-known mechanic." I am pointing out that it has not worked that way for 3 years. The previous report did not go into that detail so I opened a new one rather than comment on a dead report.
Did you even try in 1.13 - 1.17? They clearly do not act that way. I can make you a video of each version if that would convince you. 1.18 reverted the behavior.
You two clearly did not read my bug report. I am well aware that it duplicates MC-243079 and stated why I created this one. It follows that if I know the bug report exists, I also know how to use the search feature.
Can confirm that it also affects 21w17a
Caused by MC-243079; reverted 1.13 - 1.17 worldspawn behavior to 1.12 behavior.
To clarify the mechanics: 1.12 respawn picked the highest block to spawn the player, but ignored leaves unless there was a solid block beneath. Since 1.18 no longer respects y value for /setworldspawn (more info in MC-245811), the behavior was reverted to 1.12 but without the check for a canopy. Reproduce: /setworldspawn beneath leaves and /gamerule spawnRadius 0 (for convivence) then /kill. You end up on top.
If they reopened and fixed MC-243079, then this bug would be resolved as well.