After 7 years in tech, i've learnt it's not like dealing with real humans. You're dealing with a business engine - never assume good intent or competence when trying to reason out why a product arrived at it's current level of success or failure
Notice you still haven’t said how Twitter is supposed to do everything Facebook does but with 1/9th the number of employees. You and everyone else have directly assumed that Twitter has decides not to work on memorialisation because they are malicious or incompetent ... when it’s possible that they just didn’t have enough people to work on it.
We could discuss if this feature should have been prioritised or not, but claiming that Twitter is this little understaffed company that cannot be expected to implement something like that is a bit disingenuous.