One assumes there is a normal attrition to boats. All manner of things happen to them that end there existence. If there is adequate production of new in that size, most don't seam to notice the loss of older boats. Clearly there seem to be a smaller percentage of these types of boats in the <35' size being made compared to 10 to 50 years ago.
Ted
Boats under 35'? Of these types? Not sure what these types are but lets suggest it's cruising boats. Now, first, can't compare 2009-15 to 2000-2008 on any type and size of boat as the market crashed and has since slowly been recovering but not to those previous levels. As to "these types", whatever that means, there are many choices in under 35'. That market has always been dominated by production builders and always will be. Sea Ray is number one, Bayliner number two. Outboards are way up, stern drives down.
I've tried to look in the broad definition of trawlers, just doing a yacht world search and look at the popular brands. Albin is still building in that range. Mainship still building. Sea Ray cannot be ignored as the Sundancer's outsell all other boats in that range. Carver still has a 34 and 37. Ranger Tugs, American Tugs, Nordic Tugs, Diesel Duck. Beneteau is new to that range and sells more volume than the vast majority of boats previously in that range. Meridian still builds in place of Bayliner.
Grand Banks was once huge in that market but they've long ago been gone from it, not just in the last ten years. Since we're now talking <35', that excludes KK. Halvorsen does now only offer a 44'.
One shift that is definitely seen in under 35' is the shift to Center Console that is a huge growth market due to the larger outboard motors available now. World Cat is doing well with their Glacier Bay series. They didn't even start until 1986 and they're the largest manufacturer of power catamarans. I have a friend who just chose a new Glacier Bay vs. an older Albin as he was getting tired of looking at older Albin's (which is what he had his heart set on) only to be disappointed in their condition. For a 27' multi-use cruising boat the Glacier Bay is very functional and very inexpensive comparatively. A comparable boat in an inboard would cost far more.
What I see missing is tons of boats where someone made a deal with a Chinese factory to make a few to order, there was no "builder" as such, just a "procurer" getting them built and often not in the same factory.
I am still missing the point of what is missing? Are we upset because they don't go as slow? If we're talking late model used boats, there's a shortage in all as you weren't building many boats from 2009-12. If we're talking volume of boats I don't see the change being discussed. If we're talking number of brands, perhaps I see it as there aren't as many of the 1 or 2 boats a year builders on every street corner. Most of the small custom builders are in SF. That's why my wife is beating her head against the wall as we're both really just trying to understand what we're saying is missing. There was a statement made regarding the ongoing trend of builders not offering their smaller sizes but I see more of that in the 40-70' range, not under 35'. The title is where have all the smaller trawlers gone and the OP hasn't said what they mean by that, which smaller trawlers, and it's being followed as if something is gone and for those relatively new to coastal boating, but having done lots of research, I remain confused.
What is it you're looking for and can't find? And don't throw price out. That's an entirely different question.