While I agree, I think that getting more games on Linux is far more useful. When Linux is almost 3% very few studios will care much. If they can do a small bit of testing on Proton and maybe work around a bug or two they are far more likely to do that then make and test a native build. If this then gets Linux usage to 5, 10 or 20% that will drive more native builds.

So I agree that it somewhat reduces the incentive to release a native build. But I think that is outweighed by the benefits of making the Linux gaming experience better today which will have a greater impact on availability of native builds in the future.