Debt isn't a useful measurement. As long as we have a deficit the debt will increase naturally. This would have been especially true post-2008 and for many years after that as we entered recession and the deficit increased.
At lot of this is tribal. Labour complaining the Tories have increased the debt as if they wouldn't have, as if anyone wouldn't have, after coming into government and the Tories lifting policies from Labour's 2015 manifesto that they deemed economically stupid then but helping people now. I remember the howls of derision pointed at Miliband for the cap on energy prices and now it's going to be Tory policy just two years later. Labour are promising to protect the triple-lock (which is bad policy) and the Tories aren't. The 'proper' socialists leading the Labour Party are going to rule out tax rises for '95% of people'.
I really do think you could take the Tory Manifesto, package it as Labours, and give it to a Labour supporter only to hear them gush about how much better it is than the Tories and the same the other way around.