That’s not true, most ISPs have vast blocks of IP ranges and issue one address to each customer device, the NAT occurs behind the local router.
Maybe Finland is different, but there are a total of 14.3M addresses allocated to ranges in the country and a a population of only 5.5 million it seems unlikely. Are you maybe confusing unique public IPs with subnets or ranges?
The below data is pretty old and incomplete, but gives some sense of scale:
Finnish ISPs
| Owner | Total Addresses |
|---|---|
| Alajarven Puhelinosuuskunta, JAPO | 8192 |
| Alands Telekommunikation Ab | 40960 |
| Blue Lake Communications Oy | 16384 |
| CGI Suomi Oy | 8192 |
| CSC - Tieteen tietotekniikan keskus Oy | 262144 |
| DataCenter Finland Oy | 8192 |
| DNA Oyj | 1699840 |
| Easylinehost Finland Oy | 32768 |
| Elisa Oyj | 3526656 |
| Enfo Oyj | 4096 |
| EPTE Oy | 4096 |
| Equinix (Finland) Oy | 106496 |
| Etteplan Oy | 8192 |
| EURAJOEN PUHELIN OSK | 4096 |
| European Backbone Networks Inc. | 8192 |
| EuroQuest Oy Ltd | 4096 |
| Exomi Oy | 4096 |
| F-Secure Oyj | 4096 |
| F-Solutions Oy | 8192 |
| Ficolo Oy | 8192 |
| Fujitsu Finland Oy | 24576 |
| Harkatien Puhelin Oy | 4096 |
| ICT Elmo Oy | 32768 |
| Ikaalisten-Parkanon Puhelin Osakeyhtio Ltd | 8192 |
| Jakobstadsnejdens Telefon Ab | 49152 |
| Kaisanet Oy | 57344 |
| Karjaan Puhelin Oy | 16384 |
| KaseNet oy | 8192 |
| Keski-Suomen Valokuituverkot Oy | 4096 |
| Laitilan Puhelin Osk | 8192 |
| Lounea Palvelut Oy | 77824 |
| Maxisat Oy | 8192 |
| Mediam Oy | 8192 |
| Microsoft Mobile Oy | 8192 |
| MMD Networks Oy | 4096 |
| MPY Palvelut Oyj | 24576 |
| Netplaza Oy | 20480 |
| Nokia Solutions and Networks Oy | 8192 |
| Nyttab Ab | 4096 |
| Online Solutions Oy | 4096 |
| OpusCapita Group Oy | 8192 |
| Otaverkko Oy | 8192 |
| Oy KD-Soft Ab | 8192 |
| Paraisten Puhelin Oy | 8192 |
| Pirkan Opiskelija-asunnot Oy | 8192 |
| Pohjois-Hameen Puhelin Oy | 12288 |
| Pohjois-Karjalan Tietotekniikkakeskus Oy | 8192 |
| Pohjoisen Keski-Suomen Verkkopalvelut Oy | 4096 |
| Puhelinosuuskunta LPO | 16384 |
| Sanoma Oyj | 8192 |
| Seclan Oy | 4096 |
| Seltimil Oy | 4096 |
| Setera Oy | 8192 |
| Sofor Oy | 4096 |
| Suomi Communications Oy | 28672 |
| Tele-entre Oy | 4096 |
| Telia Communication Oy | 200704 |
| Telia Finland Oyj | 2539520 |
| Telia Inmics-Nebula Oy | 143360 |
| TNNet Oy | 36864 |
| Ukkoverkot Oy | 4096 |
| UpCloud Ltd | 32768 |
| Vakka-Suomen Puhelin Oy | 16384 |
| Veikkaus Oy | 8192 |
| Verizon Finland Oy | 24576 |
| Viria Security Oy | 8192 |