I feel like regardless of the reasons they did it, whether or not it was necessary, they lost a lot of good faith with the users when they locked the GME and crypto trading during that whole thing. I have no idea how necessary their actions were but regardless of its necessity it still cost a lot of user good will.
I think it's more likely that Robinhood's rapid rise was fueled by COVID boredom and a wonky stock market where it felt like everyone was getting rich from stocks and options.
Now that the market is cooling off and a lot of their new users got burned when they learned that the market doesn't always go up, I suspect a lot of them are losing enthusiasm for frequent trading.
They did their IPO at just the right time.