The gov.uk ADRs about their AWS choices are public, if folks are looking for more real-world examples: https://github.com/alphagov/govuk-aws/tree/master/docs/architecture/decisions
I like those and are by far best than nothing. but I find they lack to highlight trade offs and the alternatives. Knowing why something was discarded or a branch of the decisions tree has been dropped is a good thing to keep around. I mean afaict those keep only the good nodes in the traversal.
Imho the search for the optimal architecture of a system is a parameter optimization problem, and keeping all solution space and decision functions available helps to be less greedy and have a more holistic solution.
I think this is solved in ADR with 2 mechanisms: