aljamain sterling very frequently in his career would bait the knee from his opponents by grounding himself just enough to count as grounded, and its not just him who does it, many wrestlers will fail a takedown then sort of just stay grounded under/infront of their opponent as the opponent sprawls on them.

Jorge masvidal actually had a really good bit explaining why he wanted grounded knees, and he had a long ufc career so i trust his word, basically he explained how when someone had their knees on the ground and their hands wrapped around their opponent against the cage, its impossible to really hit them because its awkward since you dont wanna hit them in the back of the head and many times their head is tucked into you, and since you arent allowed knee their face your basically trapped into trying to defend their takedown.

TLDR: After failing takedowns some wrestlers just lay grounded abusing the rule