What is exactly the thought behind having these companies that make billion, not pay taxes?
The GOP theory is that when the rich get richer, it trickles down and helps the economy. In reality, the companies use their windfall to buy more of their own stock, which enriches those who own the most stock, i.e. executives and large shareholders. A rising stock market also makes regular folks "feel" richer, even if their stock ownership isn't anywhere near as much as the rich have. While it's true that the wealthiest people likely spend more, there are only so many houses and yachts one person can use, plus they may be spending between each other, e.g. buying an expensive house or painting from a similarly wealthy person. This was all known in advance of the tax reform last year. Gary Cohn was speaking to a room full of CEO's before the tax plan passed and they were asked how many of them planned to increase capex spending after the tax cuts and almost none of them raised their hand. It was self-serving by Trump too. Parts of the plan looked custom designed to benefit his business, which he did not divest from, and although he told people the tax plan was going to be "very bad for me, believe me", estimates are he profits about $15M per year from it.
In some of the cases the companies get tax credits for various things, typically pushed for by lobbyists. Or they get tax breaks from States to invest, like Amazon does. Ubi and I assume EA benefit from tax credits in Quebec, up to 37.% of developer salaries iirc.
It's important to remember too that the companies are paying taxes, but much of their taxes paid are elsewhere, and the US (rightly) doesn't double tax.