"Austerity" in 2010 wasn't just about avoiding higher taxes and borrowing - it was a political decision to cut the size of the state, in the misguided impression that it was "crowding out" the private sector. For many Tories, cutting the size of the state was probably an end in itself, but without the huge levels of growth that were supposed to come, it didn't allow for the accompanying tax cuts that they wanted. Crowding out as a concept didn't exactly set the world on fire.
Remember that one of the core principles of Osborne's Austerity was a public sector pay freeze. Given that today we've seen all the recommended pay rises accepted, it's clearly nothing like the same as 2010.
Labour are also banking on growth, but to allow them to improve public services, rather than cut them. Whether it works, we'll find out over the Parliament, but despite what Reeves said today, they are still promising to do more, rather than less.