I had removables for maybe 7 years - because I didn't wear them enough. Lower with a screw to push the front teeth forward, upper Hawley with various springs. They were doing pretty well until I went to university - then I only wore them at night - and not many nights.
By the time I came back they didn't fit, so I stopped going to appointments, and that was the end! They have relapsed, but not terribly, but I may go for treatment again - probably.
My first treatment was free (in the UK), but the next one wont be. Hoping I can get it done with removables but hardly any orthos seem to use removables on adults.