Nostr is open source, things like "trending" doesn't even exist in my client, development has been happening and very fast imo. There aren't enough developers to do all the things that are possible and that people want, even less devs that get paid somehow. Key rotation is a very difficult problem to solve, I guess because of that it's not a priority and for now we must just deal with that, maybe something based on web of trust can solved it. IP and Metadata leaks are just how nostr and the internet works, my advice to people is, don't use your real identity and maybe nuke your npub from time to time. But even that is being worked on other fronts, many apps are moving from url/dns coms to Nostr events, wich is already a big deal, IPs like Vitor said is the last boss, but many projects can be a solution in the future. The thing is Nostr may have some flaws now, but it's already a lot better than other solutions and it has a lot more potential, it just needs time because there is a ton of possibilities and a few devs.