@Bedrockgames
The way you are boxing us in is by addressing all RPG play via reference to conventional D&D play and treating any breaks from that as something unusual that bears special inspection rather than as thoroughly normal play that deserves as much respect. You are placing the burden on us to describe less conventional play via conventional mores. You are also using definitions of railroading, agency and especially system that are not inclusive and do not consider less conventional play. It basically makes conventional D&D play the standard for what an RPG is (which I think is horse hockey).
If you are going to address roleplaying games broadly than it is on you to show some awareness and respect for less conventional play if you are expecting respect for your play.
You might not mean to be disrespectful, but expecting discussion to start from a normative baseline that centers a particular set of styles and particular structures of play is decidedly no bueno (and fundamentally erases less conventional play from the conversation of roleplaying games in the general sense).