What does a fire stick do differently than using the apps on my TV?

Hard to say, guessing you have a newer "smart" tv. Roku and fire sticks are really helpful for streaming content if you have an older tv. Amazon promotes it to use with Prime video. I like BBC iPlayer and 4od.

A firestick can be beneficial to those who don't have a smart tv, it basically converts the tv to a smart tv. You can also have them 'jailbraked' and have every iptv channel installed for a relatively small charge, not legal but very common here for watching live sport and films

I use a Roku box, in place of cable. I don’t have a "smart" tv, so the Roku has various channels, plus it will connect the apps I have on my phone and tablet (Prime, Hulu, Netflix, Paramount+) to my tv.

My understanding is, the Firestick does the same kind of thing.

And here I am, thinking of those combustible sticks I buy in the camping supplies section of a sporting goods store, to help me light a campfire.

A TV app can't do that for me. 😄

It converted our old but perfectly workable telly into a smart TV for just £31. Compare that to the cost of buying a new TV.

It doesn’t really
Just a differently laid out dashboard layout of all the streaming apps you’ve either subscribed to as well as others

I use my Apple TV exclusively

I think it is just like the Roku u just have more options

Firestick likely receives more regular updates than the TV. It also might have access to a broader selection of apps than the TV. Beyond that they serve the same purpose.

You can also take it with you when you travel.Without too much trouble

You can slide load programs that allow other programs

It just offers the same stuff except Amazon is the main service

They're for people who don't have apps on their TV.

most people use them to jailbreak them