Hi Nick,
Thanks for the thoughtful, detailed comments as usual.
My peeve with Google is that they are not losing money, on the contrary: they are making money hand over fist. The least that they should do is to keep the initial arrangements that gave them total access to our data (which allowed them, at least in part, to make all that money)
So, I will probably use Takeout to migrate my photos, along with everything else.
I'm right now experimenting with NextCloud: it's free (both as in beer and as in freedom, and also as in "free from Google's prying eyes"). Right now I'm using one of the free providers, but my plan is to self-host it in a VPS -- turns out I can rent a VPS with a cheaper cost-per-GB than paying Google for the an "expanded" 100GB or 200GB One plan).
I will post about it in a new topic.
Cheers,
-- Durval.