Mastodon's search not applying to all posts is 'a feature, not a bug', as mentioned in the documentation:

Admins may optionally install full-text search. Mastodon’s full-text search allows logged-in users to find results from their own posts, their favourites, their bookmarks and their mentions. It deliberately does not allow searching for arbitrary strings in the entire database, in order to reduce the risk of abuse by people searching for controversial terms to find people to dogpile.

https://docs.joinmastodon.org/user/network/#search

I do understand the rationale behind it in that it makes it safer for people to share personal or political things to their followers without the risk of abuse from strangers, and the recommended alternative is to hashtag any post that's okay to be publicly found.

The problem with this is that there is no agreement on which hashtags to use consistently, and that people are not used to, or feel a stigma about, adding hashtags to the end of each post.

Some people consider it an overly attention-seeking behaviour, because overusing hashtags is associated with marketing and influencers trying desperately to gain maximum reach on platforms like Twitter and Instagram.

Meanwhile, on Mastodon it's more of a thing to hashtag posts with like #photography or #[name_of_videogame] when sharing things, so other people with the same interests can find them.

I think kbin/Lemmy is already showing promise as a community gathering-place, but it's nowhere near useable for being a repository of knowledge like Reddit is - if you want to know how to download videos from an obscure local streaming platform in a small country, hear experiences of doctors treating a specific chronic condition, or find answers to a highly specific scientific question, a quick search with site:reddit.com would usually give you the answer, and if you didn't there would usually be a relevant sub with someone knowledgeable in the field.

It's going to take many years for kbin/Lemmy to reach this status of a digital Great Library of Alexandria (if at all), and so much information is still going to be lost if Reddit shuts down.

Doesn't running a local instance mean your activity is tied to your API key and your IP address?

If that's the case, I feel like browsing old.reddit behind a VPN is more private and less fuss (though I'm willing to be proven wrong!)

Edit: from Libreddit's Public Instances are Shutting Down #840:

Their new limits mean the project would only work for small instances and who authenticate using OAuth, effectively voiding any privacy benefits of using Libreddit.

The community-made XIV on Mac launcher/compatibility layer has better performance than the official client, and works on Intel Macs with AMD GPUs and all Apple Silicon Macs! I play it on a recent MacBook Air and it's extremely smooth:

https://www.xivmac.com/