Are younger generations more easily offended? I'm not sure that's even the case; I think people are just being offended by different things than they used to be.
Something that needs to be taken into consideration is the effect that social media has had on society overall. These algorithms are tailored to increase engagement because of their profit model being advertising. It turns out, people are more likely to be engaged with things that make them angry - perceived threats (either real or imagined) are highly salient, and this continual targeting of the flight/fight/freeze..etc. system is making people more likely to reactivate the fight or flight response in the future.
That's just one small slice of the pie when it comes to social problems in the digital age. We live in a very different world environmentally than just 20 years ago, but our brains are basically the same for however long humans have been around. So, it's not surprising to see behavioral consequences of such a fast changing world.