Yeah we've always been fast and mobile but ultimately subject to retaliation. I think this edition minimizes the impact of that retaliation moreso than others, though, thanks to tougher vehicles, FnP on T3, and Stratagems like Fire & Fade, Lightning Fast Reactions, Hunt From The Shadows, etc. So if you're new to the True Kin enjoy! We're living it up these days.
And as others have said, you'll see the difference in practice when you lean in with the weight of your forces some place where your opponent can't entirely reach you with everything they've go, or when you've made certain slow enemy units obsolete or useless for several turns because you're playing keep-away with them, focussing your fire on the units that actually can disrupt you in the here and now.