everyone who had to take any form of (applied) thermodynamics would know

Who works in decimetres? And why would you want to convert it to litres? I’m confused.

No, anything more complicated than a quarter pounder is getting ignored by most people

No, I don't think so. I didn't know that offhand, but I guess I could have easily derived it from knowing that 1 mm^2 = 1 ml. Most people probably couldn't do taht either though.

I've never seen anyone use decimeter in any practical setting, but in my field it is common to use mm^3 and mL interchangeably

No. Cubic metres are confusing.

1 m^3=1000l is likely also hardly known.

60% of people don't write in Latin letters.

1 (Decimeter)^3 = 1 Liter? I don't know. It's probably a lil bit more unknown to people who don't use the SI system.