If you are old enough to remember what it was like trading prior to about 2010, you could short about any stock you wanted intraday. You could short sell whatever the hell you wanted, from the most obscure thinly traded stock to the biggest names. There were no extra costs or restrictions (for stocks under $5 you needed $5 per share in cash per share shorted).
The reason why things were so liberal back then was they were not strictly enforcing the rules requiring brokers to locate shares prior to allowing the short sale. So basically the broker would create a marker and sell them naked.
Then came Overstock.com and the CEO's war on naked shorting. Thanks to him and many others, the SEC began a crackdown and changed the rules requiring the broker to have the stock in actual inventory or have a source to borrow PRIOR to allowing the short sale.
It was a lot easier to daytrade back then. I remember trading Fremont Financial back around 2007 during the beginning of the Financial Crises. I would borrow and short 10,000 shares of Fremont at $8, the stock would fall to $7.65 intraday, I would put in a bid a few cents higher and walk away with a few grand. Easy.
Today the only way to short is to buy puts - and they are not cheap. The best names are expensive as cluck as the puts for sale gobble up most of the profit. If you are lucky you make a nickel, and you have to risk lots and lots of money.
The game was rigged in favor of market makers, since they are the only ones allowed to naked short to make "a bonafide market". They can do pretty much whatever the cluck they want. Create phantom shares, sell more than 100% of the float (yes there is lots of proof of this), etc.