EULAs can impose limitations on how you use on-premises software. Sure, you can ignore the EULA, but you can also do so on SaaS, to an extent.

With SaaS, you can be monitored and banned at any moment. With EULAs, at worse you can be banned from updates, and in reality, you probably won't get caught at all.

Are EULAs even enforceable? SaaS at least have the right to terminate service at will.