Many people with disabilities play Niantic games, and there may be some that even enjoy trails. I know of many in the US that are accessible to everyone, even those with disabilities.
I wouldn’t consider this area, where the OP is trying to nominate, as being urban. There are many fields, which they mention in both the title and description, so in a more rural area. Also, Street View here was last updated in 2009, which is very common for rural areas. I myself grew up in a rural town, and Street View there was last updated in 2012.
Niantic allows trail markers and has criteria clarification on them. While you may not personally like them, they are allowed, and we are not to let our subjective views on certain eligible POIs to influence our reviewing/submitting.
This really isn’t the thread to be debating the trail marker criteria, as the OP was asking for help with their nomination. Please consider looking for another thread on the topic, like this one: