It probably depends on what you consider as being in good health ... I suspect we might be turning a corner towards choppier waters
For OO gauge, a large number of the more popular subjects have already been produced in a variety of liveries to a high standard of model. Of course there are some gaps, but not huge gaping ones to aim at and more niche choices of subjects are left. This has to increase risk for those choosing what to produce next.
Rising prices doesn't sit well with stagnating wages, rising cost of living or an abundance of second hand models which have been produced in previous years which can still attract prices higher than they were originally purchased for
an aging market - I'm not convinced as many newcomers will be enticed into the hobby in future years. Less interest in spotting or modelling at a younger age to then bring folk back at an older age with more time and money later in life
We might never have had it so good at the moment, but I do worry where its heading