I am biased saying this, but I really don’t think Lemmy is bad behind the scenes. On the contrary, I think it’s revolutionary from a technological perspective, not only because of the Fediverse but because of the way it’s implemented and all the great new technologies used.
Keep in mind that this is a FOSS project, and there is obviously no budget to be hiring moderation teams for CSAM like software giants do.
CSAM was an obvious problem from the start, but when it comes down to it, it’s a moderator job and not a job for the actual software to do.
Thankfully there are new tools now to help moderators deal with CSAM that are possibly going to be incorporated to Lemmy afaik.
TLDR: Don’t blame the software for people being shit