Tbf all of these tools - and Pixelfed more than most - are so very new, and being developed on a shoestring budget using volunteer efforts that are not seeking capitalistic remuneration. And being able to pull in old posts is a very niche feature that affects an instance pretty much only once, upon its initial creation and then never again, so it might not be a top priority for its dev team to implement. Though a lot of teams for Fediverse tools (like PieFed) tend to be quite responsive, and pinging them may help them realize that it needs to be done sooner, i.e. communication of that may be helpful rather than annoying?

Whereas ATproto’s main downsides lay in it lacking “robustness” for the future - what happens when like pretty much every Internet company that ever existed (Google, Meta, Amazon, etc.), they decide to switch from attempts to attract a wider user base to trying to monetizate its content? Suddenly all those ATproto connections become a liability where someone can access the content held hostage therein without having to watch advertisements that benefit the main branch, thereby switching the collaborative model to a competitive one.

ATproto is strictly better in the short term, and will cause much pain later on, as opposed to the Fediverse that has some onboarding and ongoing pains now but to some people offer better hopes for the future of a more unfettered/unconstrained method of interaction between people, where control is placed more democratically into the hands of the end users rather than centralized authorities.