It is just a bubble. The fact that most passives are easily available confirms what is already obvious: the demand for the end product is not significantly larger.
I think your conclusions are wrong.
1. Making passives isn’t nearly as difficult. There’s a lot of manufacturing capacity, and it’s easier to ramp up than semiconductor manufacturing, which is insanely complex and time-consuming. The start to finish process for modern semiconductors takes around 3 months due to the sheer number of steps involved (about 700 steps).
2. The high availability of passives is likely partly due to the fact that they’re useless without the semiconductors they’re used with. No chips = no boards being made = less passives being bought + factories still pumping them out = plenty on the market.
https://www.kitguru.net/channel/generaltech/joao-silva/passive-components-may-be-hit-by-shortages-too/"According to DigiTimes, Chemi-Con, Nichicon, and Rubycon are responsible for over 50% of the capacitor market worldwide. Currently, most of their factories are located in Malaysia and Indonesia, which have been lockdown during August and July due to the increasing number of Covid-19 pandemic cases found in the population. Unfortunately, the lockdown severely affected the factories, forcing the companies to reduce working staff and production, which resulted in a 30% to 60% decrease in shipments."
"Lead times for the passive component order are also increasing significantly. Usually, customers need to wait four to six weeks to get their order. Now, lead times range from three to six months. To make things worse, the demand for these components has skyrocketed in the last year. They are used by a multitude of products, including 5G, consumer electronics, electric vehicles and renewable energy technology. As these industries grow, demand for capacitors has increased proportionally.
With the lack of capacitors from these companies, Taiwanese component manufacturers have become the go-to alternative. During H1 2020, these manufacturers’ YoY revenue grew by 20% or more. The shortage is expected to last for the rest of 2021"
So short version.
Capacitors made in Taiwan are taking up (some of) the 30% to 60% decrease in production in Malaysia and Indonesia based factories.