maybe I’m forgetting all the benefits of time capsule but you can plug any old storage device into a Mac now and turn it into a “Time Machine.“ It’s pretty turnkey at this point. What would a modern time capsule offer besides maybe remote back ups?

oh no, absolutely- apologies for the confusion.

Time "Machine" on MacOS continues to work (though it's clearly not as important to Apple as it once was).

The issue is: if you want to back up a phone: it will take space from your laptop and it must be tethered to do the backup. This means that if you have a 1TiB phone, like I do, you need at least 1TiB of local disk on your laptop to be able to do a single backup if the phone is anywhere near full.

This is in contrast to how Time Capsule works right now for MacOS, whereby you have an SMB share (like, a 100+TiB NAS) and your laptop will just back itself up when it can.

Such a feature would be pretty killer on iPhones/iPads, or having a "photo server" to offload your photos... idk, but Apple won't do it.