I guess I spent too many years in the electrical industry and have seen way too many devices of all types that were hit with power surges or lightning strikes. Some of the devices suffered non-passive failure. I would rather this type of failure be outside not inside my RV. YMMV
But I am a big believer in my PT50C and absolutely will never plug in anywhere without it. I'm such a fan I actually have two. One that I have been using for the past 5+ years (full time) and a spare still in the box. Well worth the peace of mind for me.