As discussed in this thread: (and I would imagine many others dating back to the origin of SPM)
There is no central/authoritative easily discoverable index for Swift packages that provides useful and commonly sought functionality which naturally falls outside of the natural domain of the Swift stdlib and of foundation.
It's fair enough to state that users ought to just search Github et al. and do their own research on which package suits their needs, however for many tasks, be they very domain specific, or broad (e.g. GPIO on the Raspberry PI, or 'HTTP Server') an average user would be well served by a community effort to highlight which packages are deemed well respected and well designed.
Swift is now (publicly) half a decade old and there's still no user-friendly way to browse all available packages for the language. (p.s. 'Hot take' which I probably shouldn't air: this mirrors the personality of the language itself - if you're a CS hotshot this isn't an issue, but for those of us that are mere mortals it's somewhat forbidding.)
May I humbly suggest that those who control Swift.org officially bless a subdomain of swift.org (say, http://toolbox.swift.org as a nice Easter Egg to classic Mac OS) which could host an index of links to git repos of packages?
Of course it would require oversight and moderation, but that could be taken on by the community.
I'm sure that this idea has many flaws which I haven't considered - but I think it ought to be considered. Perhaps there's a super-secret plan already in the works from the FruitCo(tm) that will be unveiled with great applause in early June, but as with many things we can't assume anything given Apple's modus operandi....
Shoot me down, or not, I would like to see this and would like to see more discussion about it...