The problem isn’t necessarily flipping houses, if the ones doing the flipping really are improving the property and are able to refurbish old properties to be more appealing. If they put in the work, they deserve to make money off of that - but they only make their money if they sell.
The problem is corporations who buy up housing stock, with no immediate plans to resell. They view houses like a commodity, and if they constrain supply in certain areas they can artificially create profit. This profit, though, comes at the expense of everyone who is looking for a home at the time.
I think the solution is for localities to step in and crank up property taxes for residential units that are not either occupied or actively on the market. Once a company keeps a property off the market for a year, make it much more painful for them to hold it for another year.