@Scott Christian I get what you have against the current familiar rules. I even agree that it isnt ideal.
But dont misrepresent my arguments in order to make your own.
I have said more than once now that i do not experience the "treating the familiar as an item" behavior you are so worried about. No one is sending their cat down the hall to trigger traps, in any game i have played in or run.
But unless you have a game where the pcs spend as much time at camp as in the dungeon, and familiars have something to do at camp, people are going to take familiars into dungeons. And familiars are gonna die as a result, even when it is basically a character's subclass (or close to it).
And that is fine under only 3 circumstances.
1) the familiar isnt down foe that long. Literally just let it make death saves regardless of how much damage it takes, so that a spell slot must be spent to being it back just like a PC, and this wiuld be much less trivial.
2) The familiar doesnt matter
at all in any mechanical sense. Pure flavor. (the worst option IMO)
3) The subclass or whatever gives you enough besides the pet that you arent half a PC while the pet is gone. (My oldest BM rewrite focuses on this, making the BM themself a master of teamwork, so that their abilities can be used alongside the party rogue or fighter, even if not quite as well as with the pet)
The other branch of design is to make the non deadly part of adventuring and make it require more ability checks, and design familiars to be meaningful help in those things, and then make it really easy to keep the familiar st home most of the time and call it to you when you need it's help deciphering a riddle in draconic or whatever and then send it back, making it an NPC you interact with at home base and between dangerous scenes.