Well, I wouldn’t say Smooth is necessarily better. It just depends on the purpose. For example, Smooth can give sometimes a jiggly effect that you might not want for a specific context and that’s where Linear would be perfect.
In any case, thanks for putting up those demo vids.
I use a variety of browsers in Windows, including Firefox, Chrome and Edge (eww… only when I’m at work), and experience the same thing, with no rhyme or reason, in any thread where streamable embeds exist.
Discrete is also needed for some parameters where interpolation is not possible (e.g. strings) or does not work good (e.g. the color values in the Color Grading filter). Yes, the color values can be interpolated linearly or smoothly today, but the results are like not what you want/expect. In the case of strings, imagine if the Text filter let you change the text itself over time. That is theoretically possible but not yet available.
People should not use the free streamable service for something like this, a tutorial resource. But I guess that service is not totally obvious that it is an ephemeral video service when you use its free account: