After steeping, you need to dump the used leaves (assuming you aren't planning to re-steep) with more potential for spillage than when disposing a tea bag, then take the strainer to the sink, add a tiny drop of dish soap, rinse the strainer, and find a place to dry it (e.g. over an empty jar).
It's not difficult, and the extra steps are personally worth it as loose leaf tea generally tastes better. However, for people who aren't concerned about the taste difference, it's nice to have one less task (where spillage is a concern) to pay attention to.
> You need to take a spoon (extra tool), scoop out the loose leaf tea from the container
I tilt the container and use the Earth's gravity to get them leaves out. I'm not afraid to use my fingers when no one's watching! With puerh it's more of a fight, I'm not afraid to use whatever's at my disposal to pry the leaves out the cake.
> you need to dump the used leaves [...] with more potential for spillage than when disposing a tea bag
Yes but it's more ecological - the leaves can be composted while the tea bag can't.
> (assuming you aren't planning to re-steep)
I definitely am planning to re-steep. With puerh, I'm even going as far as disposing of the first two steeps. I'm too fancy to drink them!
> then take the strainer to the sink, add a tiny drop of dish soap, rinse the strainer, and find a place to dry it
The gaiwan goes inside the dishwasher like everything else.
That depends on the tea bag. Some can't, some can:
https://teahow.com/can-tea-bags-be-composted/
The store-brand tea bags I buy for iced tea recently got redesigned to remove their staple. I assume that was to make them compostable, although I should double check.
I prefer tea bags because it's still easier to clean up, even though taking a dripping wet bag out of the cup is a messier process and is trash. A gaiwan or even teapot is rarely compatible with my normal in-the-moment tea drinking style. I aspire for it to be some day.
Using a gaiwan is just so joyful: stuff it with leaves, keep an eye on the temperature and steeping time, and you can resteep good leaves many times and get so much more out of them. Each of the steeps is different, you can see how the leaves open, how the taste develops. I have some Chinese greens that go on forever, start with around 75°C and 10 seconds, and gradually increase both over perhaps twenty steeps, ending with boiling water and brewing for however long I forget about it. Thinking about it, I'm off to make some tea :)
Filling a paper tea filter is pretty easy though, just grab one, and shovel in a bit of leaves with a spoon. It's faster to fill a tea bag than it is to boil water for a cup.
Uh, that's not how loose leaf tea is used...
Usually one would use a strainer or a gaiwan. Your point still stands, tea bags are less hassle, you just won't get to drink fine oolong or puerh. I don't mind cleaning the gaiwan - taking out the leaves takes a couple seconds.