Earlier quoted context omitted.
"Trickle down" is an economic slur, it's not something economists believe. It's just what some people call a certain policy set.
The term they use is 'supply side' economics - meaning, you support businesses with tax cuts, subsidies, Quantitative Easing, then the 'core' economic mechanisms are healthy, people get hired (i.e. trickle down). As oppose to 'demand side' i.e. give tax cuts or money to the poor - they spend it, the economy grows.
Would you rather live in a world where there’s only 1 large firm because over regulation has created a high barrier to entry and little incentive to risk starting a competitor, or a world with many firms where it’s easy for people to compete and they’re incentivised to do so?