@zooma You make an interesting point and remind me of a discussion I had with an aero-modelling friend some years back (he used to fly at Aughton, Halsall and Woodvale, places you may be familiar with).
We agreed that the underlying motive was pretty much the same as when we had toy boats and planes as kids, though he admitted it had taken a while to accept. For me it’s always been aesthetic. I have very nostalgic memories of Sutcliffe boats, their clockwork sub and Star yachts sailing at New Brighton. In imagination they were far more than they appeared in real life. This did however cross over with a burgeoning interest in ‘real models’ in the early 70s: an Eeze Bilt MTB kit in my case, Veron tug and of course Airfix kits.
Perhaps it’s just a matter of complexity? a toy is something which is usually ‘plug and play’ with not too much attention paid to scale accuracy, almost a caricature in some cases. A model I’d suggest, usually involves a fair investment in time, often money too, is built by or for the owner using specialised knowledge and is often unique rather than mass-produced. If scale, the owner will probably have paid attention to realism. If it’s something else then it might be very specialised or built to strict rules for competition.
That said, I’ve been really impressed with what’s available ‘off the shelf’ these days. I occasionally see kids with toy RC boats on our local lake which I’d have been more than happy with when I started off. I often wonder if many of them develop a lasting interest. Unfortunately I suspect not, and I never see kids with toy yachts these days.
This causes some confusion sometimes though, as it's been assumed on a couple of occasions that I've just bought my models. 'Where did you buy it?' and there is surprise when I explain.
I’m sure some modern off the shelf products could be and are used as the basis for serious projects however.