I mean, landlords are going to pass on their costs directly to tenants. If you raise property taxes, then rents simply go up. None of these tax increases are going to magically make a 20% down payment appear in someone's bank account that they could use to purchase something outright. None of these tax increases are going to prevent people who legitimately want to rent from renting. (Some examples: apartments that are $30k a month for rich people that need to live in some city for 3 months of the year. $8k/month assisted living facilities for rich people that are now old and need access to care while still living alone.)

Probably the most realistic thing to do is to simply implement rent control. "You can't legally collect more than $X/month in rent" fixes the problem of rent being too high. If that makes owning rental units unpopular, so be it.