(We're talking repairs rather than upgrades.)
And if you are into mountainbiking - there is also a fair amount of chance you might break something like a derailleur and spend a few hundred to fix that.
$1000 groupsets simply don't deteriorate in the manner you describe. Source: I rode many thousands of kilometers on my gravel/adventure bike, including a 1000km ride around Kenya (very dusty, rocky roads where there are roads). The only two groupset components I needed to replace on this 2016 bike so far were the derailleur hanger and a jockey wheel. The former got bent due to carelessness on my part and could have been straightened, but I chose to replace it for structural reasons. The bearing in the latter got a little sticky and so I replaced the jockey wheel.
Each of the two parts cost the equivalent of US$15 here in the UK.
I think this is a very long way from replacing the entire $1000 groupset, which was what the post I was replying to suggested.
I am talking about the groupset (the shifters, brake levers, brake calipers, derailleurs, crankset, bottom bracket, chain and cassette).
There are indeed some wear items (chain; cassette, especially if the chain isn't replaced when worn; brake pads; brake rotors) but, apart from those, a looked-after quality groupset can last decades.
Parts are often higher priced than what lots of people pay for complete bikes (e.g. a set of disc brakes 400$, a MTB fork 1000$, a groupset 1000$, a wheelset 800$, a dropper post 300$, etc). And the associated repairs like a brake bleed, a shock service or a wheel rebuild might take time and will have a high cost too.
You don't have to look into ebikes. On Mountainbikes that are used as intended parts break often enough to keep mechanics busy.
Ebikes might however indeed bring the higher priced bikes to a higher amount of people.