(I don’t criticise taxation - strong progressive taxes are important - but I say properly filing taxes for marginal, irregular, and small incomes like donations or “ad revenue” is a lot of tedious work.)
Well, I don’t think things like coffee machines are the right place for a mobile phone OS anyway. What would actually help SFOS as a system as well as every app developer, would be an update to Qt 5.15. Adding another API like an “ad platform” just adds to Jolla’s maintenance workload and will make an update to Qt even more unlikely.
In my opinion, thinking bigger for SFOS would mean focussing on future-proofing the system to make sure it survives even if Jolla (or any successor) goes downhill. This requires a) as much openness as possible (lipstick, Silica, default apps etc. under GPL), b) focus on keeping core parts up-to-date (updating Qt), c) creating a contractual framework to make sure the system stays open (like the KDE-Qt agreement; maybe this? https://forum.sailfishos.org/t/interest-to-create-a-cooperative/10799).
Adding more native support for ads diverts attention from more important issues.
I don’t share this view at all ;).