I will say that I've only had Lemmy installed for a few days and I kinda feel the same way.
Mostly because I see the HUGE potential that Lemmy has, but right now, for the most part, it's very quiet here. Maybe I haven't found the right communities yet, but most posts I'm seeing don't get very much engagement or discussion going. It feels like a ghost town here, which is sad because Lemmy feels like it has so much potential.
Lemmy is also confusing for non-techy users. I'm a software dev, and I find the federation part annoying and slightly confusing. It seems like every server has a 'technology' community, for example. Which one do I follow? I don't have time to look at each one and see which has the most active and fun discussions. That's the advantage that Reddit has: for the most part, it's really easy to discover really active communities.
IDK, I just wish there was a way for Lemmy to feel less segmented, easier to discover actually active and fun communities, and had more users. I won't leave, but I'm not feeling warm and cozy here so far.
Hardware requirements really depend on what you want to do with the server. I have a few raspberry pi, an old PC, and at least one or two old laptops to host things on. But really, I use the old PC the most. It pulls more power than a raspberry pi, but I've found it to be much more reliable and stable.
Drop some additional hard drives if you need a media server. More memory & CPU if you are doing things like manipulating images or transcoding video. I run a webserver and host various subdomains for things I don't want to pay to host. Plus working samples of my portfolio projects. I keep my actual portfolio on cloudflare, but link out to these work samples.
I also host some other apps that are just for my home network. Everything works great on a 10 year old PC sitting in a network closet. You are very likely not in need of professional server hardware.