So I am on my 5th pick-up truck in my life time and I have pretty much everything under the sun.
93 Ford ranger - Aftermarket drop-in that was "basically" for the truck but not form fitted. Protected the bed from the cargo side of things, but because it vibrated and shifted, it rusted out the bed.
01 F-150 - Factory drop in - this was a lot better than the ranger...no sliding around...very little vibration....didn't notice any issues.
2010 Tundra - Bed rug.....loved this thing. Protected cargo...no shifting or vibration issues, easy on your knees when you are moving cargo around. If you truck camp, makes a nice soft foundation for a trucktent.
2016 F150 - Loved the bed rug so much, got a 2nd one....again no issues.
2021 Ram - Dealership automatically sends all of their trucks to the Line-x place three blocks away. Customers don't usually get a choice. Love the Line-x....not slippery at all...more like 80 grit sandpaper....But I also have - you guessed it, a bed rug. I actually bought it before I bought the truck not knowing it would come with a Line-X. No biggie.
Don't have one myself, but my friend has a Weathertech Underliner bed mat...he loves it and hasn't any issues.
Just my my 2¢