Is suspension necessary for trails or can you do it with a gravel bike if you are willing to push/carry the bike on the harder more "technical" sections? Reason I am asking is 30 years ago what constituted a "Mountain" bike lacked suspension and would now be considered a gravel or hybrid bike. The suspension part is what seems to delineate a "Mountain" bike. It is really necessary? Would I be beating on my gravel bike by riding it on hiking trails?