I can certainly be wrong here. When you look into the trading scene and methods from a mathematical point of view, you see a lot of obvious bunk. So you might come too quick to the conclusion that some particular method can not work.

After that disclaimer: I think you can not compare the information loss of renko bars with OHLC bars. OHLC extracts a certain time frame from the price data. Due to the fractal nature of price curves, this is not really a loss of information, at least not for the particular time frame the system is designed for. Within that time frame, the information is complete.

Profits do not come from price differences. They come from the prediction of price differences. You need some criteria, such as a trend deceleration or some curve or candle pattern, for predicting a reversal or a continuation. Such a criteria is missing in a Renko chart. You can see the reversals, sure, but you can see not much for predicting them.

Of course the usefulness of Renko bars can be easily proven by at least one profitable system that is based on Renko bars instead of the price curve. However I haven't seen such a system yet.