What's really baffling to me is that a bunch of nerds with too much free time on their hands basically stomped out a fully fledged Reddit alternative within a few months, including multiple frontends and apps.
Yet Reddit spends millions on development every year, for no discernable improvement whatsoever, while still turning no profit.
Where is all that money going? Seriously, Reddit is a very simple site. There's nothing that hard about it. The amount of data is tiny, since the content is external, none of the resources are that time critical, a lot of content can be cached.
The ideas leading to Lemmy go back at least a decade, that I can remember. There are many little things that people figured out when developing distributed federated social media networks of this type. It's a success story of collaboration over a long time with a shared goal of making Reddit and Twitter easy to replace with a superior product.