Finland has unusually high Tor guard-relay density per capita, which matters for onion services because the rendezvous circuit involves both client-side and service-side guards. When the service side runs in Finland its local guards have low cross-jurisdiction hop counts to common rendezvous points in Sweden, Germany, and the Netherlands.
Empirically, onion circuits from a North American Tor Browser to a Helsinki v3 onion build in 3 to 6 seconds and stabilize at 250 to 450 ms per request. This puts Finland on par with Iceland for first-byte latency despite serving very different jurisdictional profiles.