[Zak]

Lazy, here, is a state. It could be understood as a temporary state like being asleep or being hungry, or a facet of one's identity.

"Stop slacking" might be better; it unambiguously refers to current behavior that a person can change immediately.

[betenoire]

I thought that maybe another language would have a word for this, and I found

https://spanishto-english.com/spanish-dictionary/haraganear

It calls "being lazy" an intransitive verb

[thomastjeffery]

Lazy is an attribute.

"Being lazy" is a transient state.

That's the important distinction here.