VSCode is 'quite ok' on Linux as gdb frontend. The main limitation is the really bare bones variable view panel. With the MS C/C++ and CMake Tools extensions debugging pretty much works out of the box and feels 'IDE like' (in that you can select the build and debug targets instead of writing a launch.json and tasks.json file, and starting into the debugger for the current debug target is just pressing F5).

The other debugger frontend that works quite ok is QtCreator.