[SubjectToChange]

The point about Syria is that if Russia and China want to fly over _any_ other country then they must assume that they will encounter VHF radar. And if VHF radar does render stealth technology useless then any include it at all in their designs? Why not slide that scale to zero? Well, probably because there are benefits to stealth and VHF radar is not as easy or cheap as you believe it to be.

You can say that the F35 trades off too much and that a "less stealth" would be better. But that's fundamentally baseless speculation.

[sudosysgen]

Russian and Chinese stealth fighter-interceptors are fundamentally based on air defense and area denial missions. You're exactly right, their main use case is not to fly over enemy countries as much as flying over friendly countries, the ocean, and their own soil.