There’s a couple of reasons straws might be convenient or even necessary:
- You have a disability that causes movement problems like shaking
- Limited neck/shoulder/arm mobility or a swollen lip (The latter makes it hard to get a proper seal)
- You wear lipstick or other makeup that could get washed away
- Your edibles were too strong
- You can build containers that don’t spill when they fall over
(Edit: Add text at the beginning instead of just throwing a list out there)
Then why not use 1? It’s closer to pi than 10 and even easier to calculate with.