Telling your home router to forward 445 is not that hard. Usinf minupnpc or just building in auto-port forwarding would be better. Alas I've seen some isp's block users from connecting to 445, which seems insane (my ispets me host there, but my parents isp blocks me from dialing home?!). So I often forward on another port (ex: 4445) and then everything works fine.
The main problem why the obvious "just use computers" problems doesnt work is... Android. Phones. These incressingly user-hostile anti-general-purpose-computing systems. Some of my media players still work with the 2017 code drom of the Android Samba Provider, but it uses old Android APIs so many media players wont work with it. I have no idea if Android still makes filesystem providers possible at all, but we havent seen any, and this one old one-time-drop artifact remains the only example I know of it ever having beem done ever on Android. But then again I really have had no interest in Box/Azure Drives/whatever... it'd be interesting/great to know if anyone does remote drives on android today. It feels wild that we have so much bespoke special software for remote media serving... when we have seemingly so little that does the general job.
https://github.com/google/samba-documents-provider
Ideally upnp/dlna should also somehow be an option too, but it assumes secure private networks I think? I'd love if it could be exposed publicly but locked down but it does all use mdns. And Tailscale's the only company on the planet who seemingly has the sense to extend our homenet's reach quickly/easily.