When I bought Photo Mechanic, which must be nearly 20 years ago , it was sold as requiring an annual $50 support fee,
Having said that, a request for this $50 never came , and I continued to get support and updates until the next version came out, which I paid for.
For sports and event photographers, I'm not sure there is anythng to replace Photo Mechanic, and their core customers will still find it worth the subscription,
I suspect Camerabits will lose the customers who just use PM for culling and bowsing (and maybe the database), but those who make full use of what PM offers may well pay whatever subscription Camerabits ask.
My workflow has been centred around PM for years (dare I say decades) , so I'm going to have to wait and see how much the sub actually is before making a decision. Camera bits say they have '...big plans for how to add modern workflow capabilities to Photo Mechanic." so I'm a bit intrigued by this.
They also make the point that other developers have made e.g. Neofinder and C1 that, (in my words), keeping up with a new Mac OS every year, and regular updates in Windows is using up the resources they should be using to create new features, And, without new features they can't bring out an update that would bring in the money to fund the development of new features ! Neofinder (not a subscription), as a one man developer still brings out new features, but regularly complains at how much time he has to spend fixing things that Apple randomly break.
For those who have 52 minutes to spare this video, which is the second of two, gives a good idea of why sports and events photographers are unlikely to be put off by the change to a subscription. He explains how PM allows him to reduce days worth of work down to hours
View: https://www.youtube.com/watch?v=39Gcyzb1U3c
The first part is here, which is only 30 minutes and gives an overview of what is explained in more detail in the second.
View: https://www.youtube.com/watch?v=0WGIVIbGg2Y&t=1116s