My home network is somewhat overkill ;p but so far, about £500 on compute to run VMs, >£1000 on a nas and various other offsite and local stoarage, a couple hundred quid on networking gear, and then the extra premium on smart home devices you pay for non-tracking versions of the hardware (e.g a ring video doorbell would have cost me £40 less than the reolink I ended up buying). I’ve also so far spent over £75 on smart light switches trying to find one that both works with home assistant and fits inside my really narrow back boxes without yet finding one that works, so the number is continuing to go up!
Yes, if you’ve built the network from scratch that works. Retrofitting it into an existing network however is a massive piece of work when you don’t have that single source of truth to start with however. On networks I’ve built sensibly, I’ll happily give people whatever CNAME they want to refer to their machine, but the machines actual name is descriptive, not the other way round.