The load will be spread across the network, but I guess the main benefit is that everything continues working even though HardenedBSDs official seed is down.
Every user has their own node, and everyone's node talks to several seed nodes. Even if the official HardenedBSD seed is down, there's still going to be another node to sync with.
Does that actually work out in practice? Do you/someone here have experience with that in Radicle?
IPFS in theory has a similar model, but in practice I've mostly found that if the original seeder goes away, at least part of a dataset becomes inaccessible.