There isn't a whole lot of consistency in Australia around what single-use plastics are being phased out and when. See what's happening in your state.
My Frank doesn't leak if I treat it nicely, keep it upright etc.
But I found an old Tupperware cup that functions more like a thermos with screw down lid. I can chuck that thing in my backpack and trust it to remain hot and not leak for hours. So maybe narrow your search to small thermos's.
My gf got me a custom-printed Frank cup and it's super pretty but it's leaked since day 1 and the lid is a nightmare to take apart and clean properly. They do appear to be selling non-seal sippy lids now though so I might just order one of those to get some use out of it.
Contigos are the best. Kinda pricey, but they keep stuff hot/cold for a long time and can take quite a bit of abuse before they die. I have 3 now. The oldest is 5 years old; newest is 2. They’re all a little scratched up, but they’re going strong!
Ohhh yeah it is complicated. You take the screw out to take the whole thing apart. I drink my coffee black so a quick rinse is all I need through the week and I wash them on the weekends
The KeepCup Helix Thermals, the steel ones with the twist on lid, have an anti spill platform underneath the drinking hole and seem pretty good unless you truly upend the cup. Downside is they’re a bit more fiddly to clean, the drinking hole cover is significantly stiffer, and I’m told by the frothy coffee people at work that they’re a lid off job for a cappuccino not to end up all wrong texture wise when drinking it.