Phil is correct, many, if not most niche magazines walk a financial tightrope with very little wriggle room. Subscribers and advertising are all that keep them going, there is very little profit in newstrade where 50% of the cover price is taken by distributors and retailers and overheads have to be met from the balance.
Model Boats has never paid well, the hobby is much less popular than model flying or model railways. During Covid it ceased publication for a while and resumed on a much smaller budget, contributor rates were slashed by 40% and regular contributors agreed to this in order to literally keep the magazine afloat. However, with Covid hopefully behind us, there is no indication that rates will be increased again.
Preparing a decent article for publication takes a lot of time and effort, even more so if includes a 'free plan'. A blog on a forum is a doddle by comparison. Those of us who continue to contribute do it for love rather than money but there comes a point when the love runs out. One regular recently told me that he'd rather spend a week doing other things than slaving over a hot computer. Most of us are getting on a bit and re assessing our priorities as to how we spend our time.
The internet has brought many benefits but also drawbacks including an inbuilt assumption that everything should be free. The truth is that providing any sort of content takes time and effort. (as a certain couple over in California are now discovering!) Whilst there are enthusisats who are happy to spend time sharing their knowledge and advice, as we do on Mayhem, there are others who need to generate an income to keep a roof over their heads. If they can't do this in one area then they have no option but to find another area of activity where they can and leave a vacuum behind them. (No, not you Henry

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Colin