Is it illegal to mow down weeds if growing over the sidewalk in front of my neighbor’s house?

I live on Beacon Hill down the street from a couple houses with ivy and blackberry that have grown out of control and taken over almost the entire sidewalk to the point where there’s a muddy path worn down in the turf between it and the road from people walking around. Is the only side walk on the street and on a pretty steep hill.

Reported it to the city on the Find it Fix it app and got a letter saying it’s on the property owner to maintain the sidewalk right of way, but obviously they’re not enforcing it, for right now at least.

I know the people that live in at least one of the houses are elderly renters, but not sure about the other one, and I know I could just a leave note asking their permission or hassle the property owners or whatever, but I don’t think anybody really cares so rather just cut and can myself to be done with it.

This seems to be common issue across Seattle and just wondering if clearing the right of way is within our rights or if I should just not worry about it and do what makes sense.