Let's say that I own a 5 million dollar business that makes 1 million per year in profit, and the corporate tax rate is 40%. I could take my profit and pay my taxes, leaving me with a 5 million dollar company and $600k cash. Alternatively I could "spend" that $600k to get 1 million dollars in cash interest free to invest in my company, raising its valuation to 6 million. Assuming with the investment that that the company continues to generate 20% profit, even if the tax rate stays the same, I make $720k per year after taxes. Considering I invested 1 million and I'm making an extra $120k per year, that's a 12% ROI/yr - not bad, not great. But since it only cost me $600k to make that investment, I'm really getting 20% ROI/yr. If taxes drop in the future, the ROI further increases, but they don't need to for it to be advantageous. Even if I never actually take profits, my net worth is still going up, and I can cash that in by selling the business or some of its assets at some future point.
That presumes that $600k spent on something increases the value by that much and it also assumes that you can easily scale up revenue with the same profit margin based on the value of the company increasing.
The latter is absolutely not a given and the former is only really safe if you invest the money in something that isn’t really an investment in the business.
Phrased differently, if you had a magic cash printing business like this that can safely scale up with more money you would be absolutely stupid to not do it regardless of the tax rates.
