When the car is daily driven, there shouldn't be much of an issue, but as most of us rarely fire the engine on a daily basis, the fuel will evaporate through the bowl vent and drain back out of the carb. as well.

Even with the "check valve" type filter, I doubt it does much good after sitting for a week or two. Can't hurt anything having a filter with it. The only reason I've seen them removed or filters used without the check valve is on high performance applications where the carb. bowl was being emptied out under heavy throttle. The check valve is a restriction in the fuel system.

Also, the inlet needle rubber pintle gets worn and can allow fuel to empty back out.

I try to fire the engine at least once a month, and never have to crank more than 5-6 seconds before it fires. Filter with a check valve installed.