I love meat, but I still think killing an animal for food, when you don't really have to, is an ethical gray area. Lab-grown meat is the first time we don't have to consider the ethics of killing an animal in order to eat meat.
https://slate.com/technology/2017/07/the-gruesome-truth-abou...
For the ethical part, I personally don't agree with the "killing animal for food" part. For me, it's perfectly okay to kill an animal for food and anyone who thinks I should stop eating meat is a problem in my eyes (if you don't want to eat meat, I won't judge, but please don't judge me either). Where I do have ethical concerns though is when animals are kept in bad conditions throughout their lives to minimize price. The impact is felt by humans as well, as those conditions often involve giving the animals antibiotics which leads to super germ evolution (and those germs land in the meat we buy to finally land in humans!). Hopefully we'll have minimum standards in the future for growing animals for food. Those standards will make "real" meat more expensive but most people won't care as they can eat lab grown meat.
Think of it as the early versions of a huge and complicated piece of software whose coders just sort of hacked it together from reverse-engineered APIs with zero documentation.