Spoiler: It's almost always 3-4x the value of a royal flush. So you needed $12-16k if you were playing a $1-per-coin game with a 1% edge at a pretty good clip.
And what do you earn with perfect play in that situation? The princely sum of around $30 an hour.
"$1 per coin game" is this a game where you put in $1 to play and get paid either $2 or $0 with 50-50 probability (0 expected).
And the what does it mean %1 edge? Does it mean the probabilities are such that the expected payout is 1c per coin flip?
Even though it's +EV for the player, you'd need some bankroll to ride out the variance as you could lose on X casinos in a row. Ages ago these were really +EV and you could usually just autoplay them with small bets, so the bankroll requirements weren't that harsh. Later on the wagering requirement on the bonuses grew, often making the small bet grind unprofitable, but you could still find profitable situations when played with correct bet sizing. But those needed much bigger bankroll as usually it was more +EV the bigger the bets you made, so you'd often play many casinos for just a few minutes with big bets losing your deposit and bonus, but sometimes winning big and covering the losses with profit left over.
Every video poker game in Nevada is required to be truly random. And every game has the payout for every possible poker hand shown on the game. A bit of math allows you to calculate both the correct strategy for any five cards dealt (which you memorize, just like proper blackjack strategy), but it also tells you the theoretical return of the game with perfect play.
As an example, 9/6 Jacks or Better (a game that pays nine coins for each coin played for a full house and six coins for each coin played for a flush) has a theoretical payout of 99.54% with perfect play. This puts it in the range of blackjack. And, like blackjack, you will eventually go broke because it's still not over 100%.
Unlike blackjack, you can't count cards. But what you can do is seek out returns in other ways. In the 1990s and 2000s, some casinos would compete on cashback comps. Add 0.33% or 0.5% cashback to the game I just described, and you're close to (or barely over) 100% payback. Find a game with a baseline payout of over 100% (full-pay Deuces Wild is 100.76, as a [rare] example), and you're deeper into the profitability zone.
Small returns unless you're playing higher denomination returns with a giant bankroll. Most people who do this make it a bit of a lifestyle -- pushing tens or hundreds of thousands of dollars through the machine gets you noticed by the casino, leading to free rooms, free meals, invitations to parties, etc.
Others look (or looked -- it's rarer now) for poorly planned promotions where a scarce hand pays off grandly and changes the math. Most of the life-changing wins in this space came from those sorts of situations.