"Funny, we had unprecedented growth under Reagan"
Yes, also the public debt doubled. Debt that needs to be repaid, one day.
There was also a 1990 boom under Clinton, with different conditions. Growth may have many different reasons - for example 1980 and 1990 growth happened also because the introduction of new technologies - and that has nothing to do with tax breaks only, and is often the apex of investments made well before. Or may be due to lifting regulations like the Steagall-Glass act, which then turn into a huge crisis. Or even due to moving more and more plants abroad, Mexico or China, to exploit cheap labour.
Anyway, if growth only advantages a relatively few people, it's not really a great thing. How long US middle-class salaries have been stagnant?
"Companies getting tax breaks are investing that money back into the US economy."
Yes, but where? Dividends? Buy backs? New jobs? They PROMISED new jobs, they did it already in the past, then went for funneling money only to shareholders and big bonuses. Look at what happened when Bush made a big tax discount on repatriated money. Many promises, and money went into already large pockets.
Companies increase the work force (and pay it better) if and only if they feel a real need for it - they don't hire more people just because the tax are lower - they hire new people if the see a ROI in doing it.
The 1980 created a lot of new jobs in the electronics and software industry. Then the hardware one was moved to Far East, while the software industry consolidated - less competition, less jobs.
Anyway, any tax break won't make them cheaper than someone in Mumbai or Dhaka. Also, would you accept a REDUCED salary because taxes are lower? Only this way a company would find hiring appealing. If they have to pay you the same amount, from the company perspective any tax break on salaries is irrelevant, you still cost the same. Sure, maybe you'll have some more money to spend, but they won't all return to the company.
That's why Trump reduced the corporate tax and taxes on the wealthy ones. Lobbyists were never interested in anything else. Let's see what happens, US debt is far higher than it was in Reagan times, and US economy less competitive. Good luck....