I’ve found this to be true as well. The only saviour, is a client who likes music under their audio. It can hide a bit of that echo.
One tip – I’ve found that shooting in foreign environments (offices, clinics, etc.) can mean naturally occurring audio issues, even when shooting with relatively high-end lavaliers (G3s, etc.).
My recommendation is to try to dampen your environment if it is at all possible.
I have a couple of cheap background stands that I try to set up on either side of my subject at about their height out of the view of the camera, and I drape background fabric or other fabrics (heavier is better) to try to stop echoes and other annoyances.
I’m sure there are plenty of tricks, but this has worked for me pretty well. 🙂