A slippery slope is a inclined surface, a place in space that once you are into, makes you transition very fast to a worse state, like your head hitting the floor at great velocity.
That is you can start well, in a good state, and transition to a much worse state over time. Your definition is also valid but not the only one way to interpret it.
It is an expression that has been used in literature for hundreds of years, not just in english. It is a metaphor.
Do you make youtube videos? I do, and I am very conscious of what I say on my videos because I can not say whatever I want.
I can not say words like "Covid"(extremely forbidden) "negro" referring to someone skin color or something the machine will mistake as me talking about people when I am really not.
And it is also getting worse and worse. In the old times you could say whatever you wanted on youtube, you could even post illegal things like films(posters could abuse). Now you can not, and it is going to become worse in the future and it is youtube who abuses.
The Trump and brexit events were extremely important. People did things that the status quo did not want. Before that you had people like Hillary Clinton or Bezos that believed that because they controlled most media, they controlled people as puppets.
They felt very confident that they could advance their globalist program without serious resistance by the people.
After that it became clear that they had to control Internet too. At least the mass media on the Internet that affects most people.
I don't say that as a Trump supporter, I am not even American, but I have eyes. I see media reaction when someone gets killed by police and the media silence when a Trump supporter gets killed by a democrat radical and it is just disgusting how sectarian they are.