Here's another article on the health benefits of Tai Chi, this time with a headline about the improvement of sleep but covering a fair range of other possible beneficial effects. (Apologies for my own misleading but hopefully attention-grabbing title above.)
It's a better article than many: it does actually show a picture of people doing proper Tai Chi (though all women - what happened to equal representation?); it refers to medical studies; and does not give the impression that Tai Chi is just about waving your arms around and "relaxing". On the down side, it seems to reinforce the mistaken impression that Tai Chi only appeals to seniors, and doesn't really evaluate the studies to which it refers. Perhaps that's beyond the scope of such a piece aimed at the general public, but as the recent Covid crisis has shown, with all its attendant ludicrous conspiracy theories, the level of scientific literacy amongst the general population is still lamentably low. (And before you object, I can't claim to be an expert either.) But would it be too much for the author to suggest that single studies of anything are not likely to be enough to draw hard and fast conclusions? Generally, a reasonable volume of consistent evidence is necessary to form a scientific consensus. One swallow does not make a summer, as the old saying goes, and one paper (possibly reporting a short-term study with a small sample size and which may be vague about the precise nature of the intervention) does not prove a case, though it might provide an indication of where further investigation might be useful.
I am not at all sure that Tai Chi should be marketed purely on medical or quasi-medical grounds. (And again, before you object, in our brave new entrepreneurial world almost everybody teaching Tai Chi is selling something, whether or not they really like to think of it that way; nor am I implying that they are necessarily being dishonest about the claims that they may make, though some of what they say I would regard as passing off opinion as fact.) The benefits of any martial arts practice go far beyond those of health, as any long-term and serious practitioner will tell you, and to expect a scientific quantification of them would seem as silly as wanting to see the advantages of playing the harp or drawing with pastels neatly summed up in a respectable but highly specialised journal. On the other hand, the physical effects of training in a martial art are at least potentially measurable and go some way towards justifying its existence in an increasingly materialistically-minded world.
Perhaps the simplest thing to say is that you need to try it for yourself, for a good period of time, and expect the unexpected; sometimes Tai Chi gives you something you didn't know you wanted. Bear in mind, also, that little of what is truly worthwhile comes too easily and the best outcomes will be obtained if you work hard and are prepared to practise - which can certainly get you nodding off at night.
Andrew Howard is a Chen-style Tai Chi Instructor teaching in West Dorset, UK.