If you don’t have someone to forward your mail to, you can get a “virtual mailbox”. This gives you a physical address and is pretty cheap. Many of them will send you a photo of the outside and you can have them scan it, forward, shred it, etc.
There are fees for each operation, but it’s a good way to see what your mail is while away. I use iPostal1 and it’s been pretty good so far.
I get you. The use case here is where you’re changing places frequently. So for me, I often won’t be in a place long enough to get it. I’d place other options like family before a service, but it is there.