Negative gearing could be very easily dropped from real estated and or all passive investments.
And there would very unlikely be any trade off.
If negative gear was dropped it would IMO take a very similar approach to the current non-commercial loss provision. Losses made would be carried forward until such time the particular investment made a profit and then the carried forward losses would be applied against that profit.
Over the life of the asset there would be little or no change to profit and tax paid. What it will mean is that it will be more difficult fund the purchase of an investment through the tax system in the earlier years.