Passport pages

My guess is that they just want to see two blank pages so they don't to go looking for the stamp when you exit. I have had that problem a couple of times when the exit immigration officer wanted to see the entry stamp and it was buried on another page with other stamps. In fact, I now use a sticky note to mark the page with the entry stamp.

Frank, that is a good idea to use a sticky to mark the page with the entry stamp.
Are 2-4 pages blank in your passport really because of an issue with lazy immigrations people having to find a place to stamp? Jeez, that is the height of laziness. And after you may have to wait for them in some long line. This would not be limited to Finland.
Most every stamp I have in my PP is faint. Maybe they should refill the ink part of the stamp more often.
I don’t know if those reasons are the real reasons. Does anyone know why there is this requirement?
Last time I got my PP renewed I paid extra for the extended version that has more pages to address this situation.

On a RT this would be 4 pages which seems a bit much to me.

I never really interpreted that both countries (Destination and US Return) want their own two pages to total 4, but honestly, this is general advice, not a drop-dead hard and fast rule.

Is their stamp really so big it takes 2 full pages to have the full stamp appear?

No, but if you were from a country that required a Visa, then that in itself may take up a full page, plus room to stamp on the other page.

If you have a couple empty pages, you are fine, even one page would probably get you by for a trip to Finland, they just want to assure enough room to stamp, 4 Schengen stamps fit easily on a page. The US does not even stamp passports on return (or leaving for that matter).

For what it is worth, the airlines in doing a document check, in my experience, never counted empty pages or flipped through them, and Immigration has not counted. Maybe someone on here has been turned away for not having pages (a number have been turned away for expiring passports though) but I do not recall hearing of any experiences.

Out of curiosity, I just looked up my stamps from 2018. I made day trips into town during long layovers at HEL on my way to and from Thailand.

First, they stamped on the third-to-last page when the (now expired) passport was only about half full.
Second, they aligned the stamps so carefully that all four take up only a half page.

Thank you all for the rapid answers. They are much more in line with what I was thinking. I had checked my passport too and had pages with 4 stamps, may have been hard to make out, but 4 on a page worked perfectly fine. Happy travels to you all.