If you’re referring to the irregular discolorations on the leaves, have you accidentally let any fertilizer splash onto them? That’s what it looks like to me, or a dog pissing on it. My leaves always get discolored like that near the bottom when a dog pisses on them, which is why I keep my plants fenced off now. I wouldn’t worry too much about it, though.
I’ve found that totally random discolorations on otherwise healthy leaves are usually due to outside factors. Maybe even sun burn or wind damage or something. I’ve had leaves look pretty rough from strong winds or a strong fan.
Nope, root rot causes the leaves to look all droopy and sad. It would make the whole plant look unhealthy. You’re overthinking it. The plant looks fine.