You could buy a significant amount of Finnair Plus points and earn status points in the process. In addition, you could exchange some points to tier points and get their Platinum (Oneworld Emerald) with short and long-haul upgrade vouchers.
You can access Finnair Plus here.
Finnair Plus Points Sale in 2020:
Finnair Plus Points Sale in 2021:
I was unsure if Finnair had tweaked how short and long-haul upgrade vouchers are issued to member accounts, but I can report that everything is working as expected.
Finnair issued another 2 long-haul and 4 short-haul upgrade vouchers that expire on January 1, 2024.
I have to say that this point purchase back in 2021 was one of the better decisions I made when buying miles and points.
Although I have Oneworld Emerald from BA ad lifetime Sapphire from AA, I have flown quite a bit on Finnair and put all the miles and upgrade vouchers into good use.
As a matter of fact, I have less than 20K Finnair Plus points left.
I have not phoned Finnair even once during the past year +, but have entirely relied on their Platinum customer service through WhatsApp (read more here), which is very responsive even during weather meltdowns.