Which is pretty ironic given that for most modern Linux distributions, installing from repositories is pretty secure. At least orders of magnitude more secure than downloading closed source binaries from various sources on the web.
You are absolutely right, but I stopped caring about this decades ago. Free software is available for everyone, so it is up to them to find it and use it — it is not my concern if they want to spend money instead.
FOSS will never dominate the “market”, for the same reasons that eating healthy and exercising won’t become prevalent behaviors. But nothing prevents me from doing what I want so it is fine.