Not actually what was asked for. The OP asked to be able to "back up my entire tree of photos", that is specifically not 'everything'.
But suggesting a Mac OS feature might be a solution on a request for software on Windows 10 is just unhelpful.
In addition to what Andrew said,
Just because you CAN back up everything (and why wouldn't you), it does not mean that you HAVE TO back up everything. You click the button called Options and exclude what you don't want.
For a few hundred dollars you can get a headless Mac Mini (or any Mac really) and configure it as a file server and put your data and backup drives on it. That is what I did with a 2010 Mac Mini until just recently when I upgraded to Thunderbolt drives. I was accessing using an iMac but the OP's Windows 10 machine can happily work to it using SMB also.