As others have mentioned, PCem is still perfectly usable, even if it’s no longer maintained by its original author (who is, or at least was, open to handing over maintenance to someone else, should someone step up). Since you’re on Windows, which has an excellent track record for maintaining backwards compatibility, it’s likely that the existing Windows binaries of PCem will continue running for a long time.
DOSBox is still being maintained, there are lots of changes accumulating in its development repository — but there haven’t been any releases in a long time, as you mention (the 0.74-x releases are bugfix releases of 0.74, and don’t include new features from the development branch). Its authors do plan on making a new release at some point, but they want to ensure that there are no regressions (or as few as possible), which is difficult.
DOSBox-X is also actively maintained and gets frequent releases. It has a different focus compared to DOSBox, initially concentrating on improved fidelity in order to run demoscene productions, and now expanding to improved fidelity in general.
Another full PC emulator which is still actively developed is UniPCemu, originally for the PSP but now available for a number of platforms including Windows. Its 8086/8088 emulation is close to cycle-accurate (4% off according to the UniPCemu wiki).
There are forks of PCem too, but given the controversies there I’ll avoid naming them, let alone linking to them.
It’s worth checking out MAME as well, it includes PC emulation and its developers strive for accuracy (but I don’t know how accurate its emulation of various PCs is).
Another possibility, still doable inside your modern PC, is an actual PC such as the WeeCee — it can even be configured to run quite a lot of speed-sensitive games well enough to play!