The thing that debt to GDP misses is the rates which need to be paid on that debt. For a while those rates were so low, it meant there was little reason to focus on paying down the debt, which is only going to keep that ratio relatively stagnant.

What is far more telling is the debt servicing to GDP ratio, which is far more useful in telling us how much our debt is costing us. This winds up looking wildly different than debt to GDP and has been a lot less concerning up until we've seen the latest spike in rates.

Debt to GDP - https://fred.stlouisfed.org/series/GFDEGDQ188S

Interest to GDP - https://fred.stlouisfed.org/series/FYOIGDA188S