There have been 1 or 2 occurrences were "DWARF" has been mistaken as another word for "FpDebug". But it is not.
DWARF is a format (like PDF, xml, docx, png, ....). Only DWARF is used to write "debug info", which is the compiler providing info for the debugger. Such as, what variables are used, and at which address in memory the variable is. Or where in memory the machine code is that represents a line of Pascal code.
There are other such formats, and in the past "STABS" was used. (Delphi uses yet another format).
Then there is "GDB", which is a program, and a debugger. GDB can be used from the command line, with lots of cryptic commands. Or GDB can be used from an IDE (or other GUI interface). Lazarus has done that in the past, and still can do that. But GDB is primary for C. It does have support for Pascal, but that is limited.
Using GDB the IDE could only show limited information during debugging.
GDB can read STABS and DWARF. Some versions of GDB have problems with certain bits of DWARF 3 (probably because those are not written by common C compilers, but FPC does).
FpDebug is like GDB a debugger. But it does not exist as a stand-alone executable. It only exists as part of the IDE. And in the majority of cases gives a much better debugging experience.
FpDebug only reads DWARF.
As for FpDebug and the "File Open dialog". I have feedback from 2 people that there was an issue (already fixed in the git main branch of Lazarus).
The exact trigger is not clear. It could be a Windows 11 issue (potentially also some Windows 10 with certain updates).
But it could also be some other software that is installed. Many programs install items into the explorer menu. In some cases, this is done by using dll, and those dll will run in every app that uses a File-Open Dialog.
So you should use FpDebug, unless/until you experience your File Open dialog hang.
(According to reports, you then need to forcefully log-off, but I suspect it may be enough to force a taskmanager ctr-alt-del, and kill all instance of "explorer", then start a new one / But that has not been tested).