out of the many many features and utilities. you specifically asked about the features and utility without the need of other people.
so..
i can hold it much like you can hold a bank note.

but the better use of holding bitcoin is that i can back it up so that if i lose one copy of the key i can retrieve it elsewhere.
if you lose your bank note.. its gone.. and nobody accepts a copy of a bank note (counterfeit)

if i cant trust keeping a paper key safe. i can secure it in many ways.
bitcoin does not need middle men custodians to secure bitcoin..
bank notes need banks to hold it to protect it against fear of loss by giving it to them in custody

bitcoin does not need insurance against bank failure, the decentralised nature means it doesnt need banks, nor insurance
if bank notes were secure by themself there would be no need for bank custody. and no need for FDIC or bailouts.

bitcoin secures itself so no need for custodians or insurance
banks need insurance but even when banks fail the insurance is not invoked. elitists prefer other methods which cause customer value loss just to prevent other elitist loss(the FDIC didnt pay out because they couldnt. thats why the tax payers bailed out the banks instead)

i do not need someones else signature or authorisation to pay them. they do not have to be awake when i pay them.
with a bank note you have to give it to them, meet them
with a bank account the bank has to phone you to ensure you are the real person making the transfer. and are limited to how much you can transfer without question

i can move bitcoin to another wallet i own without limit or restriction or permission or question
try and move bank money from a bank account into your wallet. ATM limits are $500, bank teller limits are $1000 before being questioned, delayed, limited

i dont even need to use the blockchain to move bitcoin.
i can pass someone a private key. a passphase seed. i can make a QR code or even a cryptic artwork. heck i can put the key into a physical coin or engrave it into metal. i can pass around bitcoin in many ways.

if you wanted to send bank notes internationally, even by postal service. even they have limits and insurances because they cannot guarantee it.
bitcoin doesnt need limits or insurance. it just works

if you wanted to set up a trust requiring majority vote (eg 3 of 5) you dont NEED a lawyer/solicitor or notary or bank manager to set it up.

other features/utility
heck if i know a person well i can think up 12 words they know well too. put bitcoin onto that associated address and just say some encrypted message via a private message app like
"what type of guitar did your dad play" -acoustic
"what did your sister want to do for a job" -actress
"what did you ask me for on your birthday" -apology

heck you can even have fun with it. like offer some out as a competition/prize. testing peoples knowledge where the first person to get all answers right wins
like
"what was first bought with 10,000btc" - pizza
"whats the pseudonym of bitcoins inventor" - satoshi
"what do ignorant people like antithesis think bitcoin is" - number
and so on
you dont even need them to reply to you to win, they can take it by themselves
 

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now here is the thing.
even though bitcoin does not NEED custodians to protect it from loss (copy keys in many ways)
even though bitcoin does not NEED co-signing authorisation

these features are available for bitcoin as a choice. so if you WANT to have a co-signer. you can. if you want to put it into custody you can. but with bitcoin you dont NEED to