There are modern debuggers around, it depends on what you're trying to do. For example, x64dbg is a Windows program that can debug x86 and x64 Windows programs

There are modern debuggers around, it depends on what you're trying to do. For example, x64dbg is a Windows program that can debug x86 and x64 Windows programs without any source code or debug symbols. WinDbg lets you debug the Windows kernel even on a remote machine. If you use an emulator like VirtualBox, the remote machine can even be on the same physical computer. Useful if you're developing drivers.