If the world's armed forces had a way of knowing where every enemy's plane or any other target is, even most of the time, then there'd hardly be a need for planes. everyone would just spam missiles.
But actually knowing how many targets there are, actually identifying those targets, and knowing where they are at which point in time, and sustaining that knowledge almost all-around the clock is the single hardest thing to do in warfare.
And thus a huge arsenal of missiles would be useless. as they would not have targets designated.
At best, one could hope to continuously poke holes in the runways - probably 3-4 missiles per runway would be enough to guarantee it being non functional (some misses are unavoidable). For several hours, or at best half a day, until the runway is repaired.
Counting all the runways, taxiways that could be used as runways and various prepared highway stretches there are - there might be a need to keep 150 targets shut for several hours to half a day. That's, say, 500 missiles per one "wave" and 1500 missiles per day, providing no malfunctions and providing no missile interceptions. So 4 days to spend an arsenal of, say, 6000 missiles. And contain the enemy to just carrier borne planes and VTOL planes which could use even shorter runway pieces. At the same time, all other target types would require additional missiles.
I think we've already had this discussion before.
You don't need massed missile strikes every single day.
Say you had 3 waves of 500 missiles over the course of 3 hours, which works out as 1500 missiles.
Your average F-35 will be on the ground for 1-2 of those missile strikes, because they have to refuel and rearm.
How many aircraft will actually survive on the ground?
And afterwards, the airbases and the surviving aircraft need time to regenerate.
How will they put up meaningful resistance to yet another follow-on attack by aircraft or even cheaper missiles?
Remember this is an illustrative cost comparison in the First Island Chain between: F-35 stealth fighters vs attacking cruise missiles
You can scale up the comparison from 100 F-35s to all 2000 F-35s which will be in service.
That would cost $200 Billion to procure.
If China only spent half that amount ($100 Billion), they could buy 80,000 land-attack cruise missiles like the JASSM-ER.
I know this is a fantastical figure, but it is just for illustration purposes.
And if we use your figure of 500 missiles per wave, China could launch 160 waves.
And if there are 6 waves per day, that is 3000 missiles per day.
It would be extraordinary if there were any F-35s still remaining after just 10 days (60 waves with a total of 30,000 incoming missiles)
There would still be another 50,000 missiles in reserve.
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And we are entering an era with thousands of surveillance satellites, providing near real-time surveillance.
So follow on missile strikes and airstrikes can be tailored to the target.
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So in conclusion.
From the Chinese perspective, for China to counter more F-35s, it's better to build more missiles than try to match them with more J-20s
