Windows has virtualisation based sandboxing and NT has object-level security (albeit not often used correctly and granularly) and macOS has (among other things) SIP and a subsystem called sandbox that does exactly what it says: it sandboxes. It can sandbox in comparable namespace terms (like cgroups v1 or v2, but more in translocation style execution since it's a MAC framework) yet it also does it a much more fine-grained level depending on what you need. It is used by launchd and applications by default, some entitlements require it so if you want to do some broad kind of elevated application, you also have to have a specific sandbox profile. It's also been around for 16 years, and comes with a ton of examples if you wanted to use it yourself to constrain some process. Yes, it can do filesystem (would be pointless without it), but also does ipc, io, network, memory, fcntl, sysctl, mach ports, sys calls, processes, ui, sockets, messaging, events and all of that including context-aware filtering and compound matching for all of them. And if that's not enough there is also ESF and NEF, the latter only working on networking. You can compare those two to eBFP LSM and XDP. If you want all of this on linux, you'll need to add a lot of custom eBPF and LSM as well as always run in a hypervisor for guaranteed IOMMU usage, but you can't use bare KVM for that either, so you'll either need to never touch the privileged kernel (not even give it a console) or you need to run Xen and use XSM.

Flatpak is just a cheap container copy. Can't do anything beyond what cgroups and things like apparmor and selinux can do, and uses a runtime to do soft higher-level policy functions that translate down to the same primitives. If anything, it's a great bundler, but doesn't do anything new policy-wise.

So, can you get the macOS-level capabilities (both low-level and higher abstractions)? On Linux, yes, but they don't exist yet. On Windows: technically possible, but since that would break most GUI workflow it's not likely that anyone is going to bother, and you're going to have a hard time recompiling windows yourself to make that happen.