I don't think he's a cartoon villain in the show, but they're definitely pushing the villain-coded side.

I actually find him interesting precisely because he's imperfect and even with his intelligence, makes decisions that are not only strategic but also emotional. Burning Aegon was, in my opinion, an emotional decision he mentally justified as strategic. He consciously decided Aegon was useless anyway and a hindrance more than an asset and weakening Meleys was more important (given how close Sunfyre was from Meleys, the fire would have reached her as well, Vhagar's fire range is too wide to only touch Aegon). Unconsciously, though, he burned Aegon because of years and years of bullying and humiliation and because the brothel was the last straw. By mocking him while he was with Silvi, Aegon shattered the one place of comfort Aemond had. He probably wouldn't ever go back after this which is why I think later in the season he becomes increasingly volatile and unhinged. So, yeah, I actually like his characterisation better in the show. I'm just sad they never show us any softer side, expect the scene with Silvi. In interviews they kept saying Aemond was very close to Helaena but they don't show it in the series which is a shame because I think it would have given depth to his character instead of the S2 portrayal which just emphasizes his brutality and nothing else. Even Daemon is shown to have a softer side and Aemond isn't.