Your premises seem wrong.
No country spends a significant amount on culture.
The US Federal government spends less than 10$ per capita on all arts and culture, Canada spends 140$ per capita, France 110 Euro per capita, etc.
All of these are a small percantage of the GDP of the cultural industry in the country, the federal government tax revenues, and of the GDP of the nation in question.
In the USA in particular, cultural industries generate over 2000$ per capita and get federal government subsidies of 10$ per capita. That is a half a percentage point.
By any reasonable measure, the USA has no significant federal spending on culture compared to the industry as a whole.
In other nations, government spending reaches single or low double digit percentages. Often this is due to a national broadcaster whose mandate includes reinforcing national cultural identity (In France, for example, half the culture budget is for national broadcasting)
Government spending of 0.5% (USA) to 7% (France) of an industry's size isn't a "significant amount" of that industry, and next to nobody would assume the industry as a whole "wouldn't survive" without that kind of expenditure.
On the other hand, the specific sub-areas the government supports probably wouldn't survive in their current form without government support. As a concrete example, a national broadcaster with a specific mandate and restrictions would end up looking more like commercial broadcasters, which exist in said nations, without direct government support. There are nations without national TV broadcasters (like the USA) that agree with this prediction.