Generally, is there a higher chance of people watching anime on a legal or an illegal site?

Probably legal. But I do think that there is more illegal piracy in anime than just about any other type of TV and movie. Also, there is a lot of quasi-legal anime watching, with websites hosted in countries with lax copyright laws but primarily watched in countries with more strict copyright laws that could not legally host the websites themselves. There is probably more quasi-legal anime viewing than just about any other type of tv and movie.

Logically, people are generally more likely to watch "free" cartoons than to pay to watch the same thing, if they don't think they will get caught.

illegal. there are far more illegal anime and manga sites than legal and crunchyroll is the only one i can think of that you don't need to pay for to use, you just have to wait to watch brand new episodes. with how much anime there is out there and more coming out every season, most people are only ever going to pay for a series they already know they like by buying dvds or blurays

Illegal. There are way too many free anime streaming sites out there, not to mention that they have no restrictions as to what anime they can have. Whereas legal sites can only stream the anime for which they have a license, illegal sites do not have this, so the number of anime available on just one illegal site can greatly outnumber what several legal sites can offer. Plus, it's absolutely 100% free.

Basically, otaku will read their manga wherever they can get them. The legal aspects of it are shouldered by whoever is posting them.

Anyone watching anime isn't worth considering, so who cares?

Legal due to sites like crunchy roll or funimation