I completely understand that practice. This world dis-incentivizes environmental responsibility.
The reason tubes are only $9 is that, in most countries, neither the manufacturer nor the consumer must pay for most of the environmental damage associated with the goods purchased. The factory can use the limited resources, & discharge polluted air, water, chemicals, etc. without paying for the impacts. The consumer can discard broken or worn-out items in the landfill, without paying for the impacts. Society at large--you and me, both current & future generations--bears the harms of the items' life-cycles.
Thus, for the individual consumer, replacing is often cheaper than repairing, although the associated resource depletion & pollution are killing us collectively (already, 19% of deaths worldwide are caused by burning fossil fuels).
With that in mind, I try to repair items rather than replacing them. Nearly all my tubes (both on my bikes & in storage) have 5+ patched holes each.

Flats are not random. They are caused by inadequate tyres. TL and tubes with slime are both the wrong solution.

Are flats scheduled? Do you get them at regular intervals or know when you are going to get your next one? I’ve gotten a huge number of flats over the years…I get them so that others don’t, kinda like all my broken bones:rolleyes:…and I’ve never known when one was coming up. They aren’t caused by “inadequate tires”. They are caused by sharp objects that are distributed randomly over the roads the bike rolls over. Even sealants aren’t perfect and can still lead to flats.

Sealants may reduce the frequency by sealing the puncture before too much air is lost but they do so at a cost. There’s the added weight of the sealant and the need for regular refreshment of the sealant as well as the added expensive of the conversion.

You can argue all you want, but at the end of the day flatting, or not flatting, is largely determined by the tyres you are running. Its a very basic concept, but lots refuse to believe it or dance around it with silly semantics. You can keep you race day tyres, flat all the time and keep believing its "random" or you can get a puncture proofed tyre and it all goes away. You decide :-)

It is not the tire. Tires with integral liners and tires that are thick and even tires that have sealant can all flat. The difference between “race day tires” and touring tires has no impact on the frequency of flats. Cheap tires from a big box store are no less prone to flats than expensive tires with 120 thread per inch casings.

Oct. 2019 I drove thru Monument Valley, then stopped for lunch in Kayenta, AZ. Then went out and looked at my tires.
They had about 30 goat thorns. I spent 5 minutes pulling them out. NO flat.... proves THICK tires work. LOL.
Still, I wouldn't want that to happen often, all those cuts could add up to wear.
My bike was safe on the roof, getting a rusty chain.
And the car tires are filled with N2. Goes all year without filling, until winter cold. Plain old air tires used to need pumping every month.
And I drill every rim for schraeder, first thing. First one has 28,000 miles, so zero increased risk of rim cracking. I never rode a mile without a valve cap. One of the 2 valves will have an old metal cap, the ones with a core wrench top. Did use this a few times. They certainly are NOT useless in any case.
In 2014/5 my bike tour in Vietnam/ China, I went 4,200 miles. Only flat was because I went with a stupid Park's patch on.

1, Presta valves are older than Schrader, hence the two types.
2. They used to be a special type of removable valve just for bicycles, and they were standard until the 1980s outside of continental europe, until someone in Taiwan said "hey, why don't we just use the valves from car tyres ?"
3 Presta valves can take much higher pressures than car valves, or they used to, like up to 150 psi, when car valves start leaking over about 90 psi, I'm not sure whether that is still the case.
4. Triathlon and velodrome bikes used to have special types of tyres called tubular tyres, which had a sealed tube and tyre that you sewed together and then _glued_ to the rim. The tube was pumped to an insane pressure (up to 200 psi for velodromes) and then sealed permanently with a special type of metal clamp on the pipe inlet - presta valves replaced these.
5 Its becoming increasingly difficult to source european sized tubes (eg 700) with car valves because they are all made for competition bikes, the standard department store bikes are getting absurd massive tyre sizes.

unrelated? found this at the gas station pump today while topping off Wifey's car tires. I guess someone had a stuck dust cap? did someone vandalize it with super glue?
https://cimg2.ibsrv.net/gimg/bikefor...f59ee983fc.jpg
sorry this one is so blurry
https://cimg8.ibsrv.net/gimg/bikefor...7067433b36.jpg