We had a big teletext offering in France too at some point. Minitel is not it. Minitel was a modem+terminal in your house. So, it was bidirectional, secure, and had incorporated billing. You were able to do all kinds of things with it: enter chatrooms, order stuff (like train tickets), register/check the results for some exams, etc.

The British counterpart to Minitel was not Teletext (a one-way system that was present throughout Europe anyway), but Prestel. It wasn't hugely popular, not on the scale of Minitel, but it did have the UK's first highly publicised hacking case leading to changes in the law: https://www.bbc.co.uk/news/technology-36306419