Robinhood is good for quick smaller trades, but their order fill is horrible. Every time I am shocked at the prices my orders fill at. I'm fairly positive they are making money front-running or from kickbacks from exchanges.
Robinhood seems like a great fit for the person who has maxed a Roth and wants a brokerage to hold on to ETFs across low-ER providers, like Charles Schwab and iShares ETFs + Vanguard ETFs as they accumulate capital.
Beyond that I can't see using it for trading or anything. If I was slanging options or speculating long/short through retail brokers, I'd be doing it on Interactive Brokers and nowhere else. (And yes, I know Robinhood doesn't do short-side work.)
Interactive Brokers is the only way to go for an intermediate person who wants to speculate and have high-powered tools for a relatively low minimum ($10k I believe, $3k or so for younger people under 25?). They refuse payment on order flow, as does Fidelity, IIRC.
Like I said I'm out of that game (minus small speculation on BTC for currency hedging purposes). I've found the love of index funds and low expense ratios.