I have been around the block with this question. As a long-time user of TMG, I was disappointed when its developmental life cycle ended. I fretted and fumed for almost a year trying to find a replacement. I already had all the major genealogy programs (Rootsmagic 7, Legacy8, Gramps, Webtrees, Family Historian, etc) and gave them all a trial period to see if I could adjust to their way of doing things. While I found good features in all of them, I just could not come to grips with the underlying data model that was based on the GEDCOM standard in each and every program. After a year of lost research time and disappointment with these replacement programs, I recently had a eureka moment that would solve my dilemma. I knew that TMG could not survive many more Windows upgrades or updates so I decided to take an older laptop (or desktop) and literally "freeze" the technology.
I started with a fresh install of Win 7 that I fully updated to the latest updates and then disabled any automatic updates for Windows7. Then I installed TMG 9.05. I added dropbox so that I could download the latest backups should the Win 10 OS stop working with TMG for some reason. I also added Word so that I could see the results of my output in a word processor, for reasons that might become clear in a moment. I prefer working on a desktop so my plan was to continue working with TMG on Win 10 for as long as the program was supported, and when the time came, to switch over to my laptop (or re-purpose one of the many desktop computers that I have).
Why did I choose this path? Simply put, TMG is the best genealogy program. Its data model is far superior to all of the other genealogy programs combined and it is a well structured relational database that does not use the gedcom standard for storing data. Consequently, the power and functionality of the TMG database is unparalleled in speed, and flexibility. To make an analogy, TMG was "Watson" while all the others were "Vic20s" and that is why I am staying with TMG until I die.
The second reason is the amount of effort that I have invested in my research. My family tree project starts in France about 1570 and includes about 90% of all the descendants of the first progenitor to arrive in North America in 1665. This amounts to tens of thousands of records with copious amounts of data including witnesses, along with stock and custom sentence structures. Only TMG was able to produce the output that I was looking for. Yes, the other programs could mimic TMG's output, but not with the resolution and accuracy that I had so painstakingly developed in TMG. Re-visiting all of the records in any import into any of the other programs was just not an option. I did not fancy redoing 35 years of research just to "make my gedcom" file work in an inferior program. There are many other reasons for staying with TMG, Plainly put, you could combine all of the best features of the other genealogy programs and the resultant program would not hold a candle to TMG - primarily because of their data model.
My personal genealogy project is to produce an encyclopedia of each and every person in my ancestral tree, by generation, complete with end-notes and citations, a bibliography, and indexes. I have about 15 generations in the family tree, and just five generations produces a book that is already well over a thousand pages in content. 15 Generations will probably produce tens of thousands of pages. No other program can produce this type of output without massive post editing, in my opinion. From my observations, all other programs crash when I try to produce an encyclopedic sketch from the gedcom data. Hence another reason to stay with TMG.
Clearly, my research may not match the aspirations of others in scope, content, or time invested. Given the fact that TMG is no longer available one is only left with the option of choosing one of the newer "gedcom" based genealogy programs. It is just not for me! Perhaps some ambitious soul will acquire the TMG data model and rewrite it so that it will work with the latest operating systems and databases. I am not a fan of cloud-based anything for security, privacy, and commercial reasons (you do all the work and someone else reaps a profit from your time and effort). I just will not go there!