Is Assimilate toxic?

I've been playing a lot of assimilating and have been starting to feel bad because I get a lot of forfeits. Whenever I use invo / double-cross/ coup de grace to play a card like Foltest the game often ends in a forfeit. I started playing non-NG decks recently and when I run into assimilate it is extremely annoying to have your best cards taken while they are able to play them even better (think thirsty dame + unseen elder), while you have little control to stop it or get it back. It's definitely not broken, but just because it isn't OP doesn't mean it isn't toxic. I don't want to contribute to an unhealthy game atmosphere but when it comes to NG I question what else there is if assimilate is toxic, because mill/clog/ball all seem to be quite toxic and anything else is a boring midrange deck.

What are your thoughts on assimilate? Is it annoying or admirable when you face it? How do you control it? Should it be changed? If assimilate were to ever become a meta would it hurt the game?