The core question is less about the cuts themselves and more about if we the people are getting what we're paying for.
1) It kinda doesn't matter if it was caused by the pandemic or not, what matters is it needs to be fixed. Cherry-picking "since the 1970s" keeps us in difficult times energy-wise which we've attempted to correct for with more spending. If you go further back, our current ratio is what it was during WWII. Do you currently see federal government production as similar to during WWII, or are we not getting value out of what we're spending?
2) Assuming we all agree with those percentages, there's still an obvious 9% to look into. At these levels, that's real money. Also, certain initiatives are way more destructive than the spending would suggest, e.g. just about everything found out about USAID impacts hearts and minds, which impacts further negatively productive efforts outside the federal government.
3) Of course healthcare is on the list. Single-payer systems have their problems, free market systems have their problems, our current hybrid gets the worst of both. So it needs to be addressed, but perhaps not "first" because the answer here is a total rework, whereas there's plenty of other savings available right now as low hanging fruit.
4) Corporations do not pay corporate tax, their customers and employees do. Why should we burden our productive populous with tax on their income, tax on their workplace before they even get paid, inflation due to government spending, etc? If the argument is that tariffs are passed on to the customer, then corporate tax is definitely passed on to the customer and the employee. Additionally, corporations are not currently benefiting from a healthy workforce (look around), or an educated workforce (steady decline since the DoE was established), or a safe environment (go to SF), or a working transportation system in many cases. Again, are we getting what we're paying for?