I have heard some "contractors" purport that gutters are a risk or that they cause damage. That's like saying that seat belts don't save lives when they are made of chenile stems. What they are telling you in reality is that they have no idea how to install a good gutter, and rather than learn or promote a fellow tradesperson who does, they are just going to decry the entire science like a flat-earther at a globe manufacturer's convention.
Properly channeling water away from the walls of your home is the only way to protect them from chronic weather related rot. Water splashes back up two inches for every one foot it falls. It goes right up behind your siding, don’t think it doesn’t. Now, your siding could be installed in such a way that it ventilates and dries naturally, but it probably isn’t. So let’s get a real solution. Gutters, like anything, have elements of design to their system. A slew of them actually, from the elevation below the drip edge, to the hidden pieces that complete the system, to basic maintenance. I know that’s a dirty word nowadays. Maintenence. Are you getting goosebumps? Don’t worry, we can install a leaf guard. Look seamless aluminum gutters are not cheap, so don’t pay just anyone to screw it up. They should be installed by a professional providing a warranty(25 years or more). Don’t attach them to a piece of garbage rotten facia board either. Your contractor can tell you if the trim should be replaced, painted, or modified to protect your investment in gutters.