Today I talked with a reputable bathroom faucet company. They claimed that their all-metal faucet and Plastic Bathroom Faucet (internal parts) are roughly the same in quality and frequency of breakage.

When they do break, they usually encounter the same problems.

This is real? As far as I know, the price of all metal faucets is higher because of their higher quality.
As far as I know, vine metals are more expensive because people think they are better. In the past few years, some plastics have more traditional performance and lower cost. However, this is just a conversation with people in the industry, so I can't really cite any sources, so I didn't post it as an answer.

In fact, the cost of metal is higher because the production and processing cost of metal is higher than that of plastic. Your logic is the opposite.

It is cheaper for companies to use internal "off-the-shelf" parts instead of multiple specialized assembly lines for each type of faucet. The "internal parts" are likely to be the same.

The additional manufacturing cost (we must ignore any marketing and supply and demand effects*) comes from the fact that plastics can be injection molded cheaply (once you have a mold), and metal casting still requires many additional steps in casting and precision During processing.

Every piece of cast metal you have ever owned is made of a (disposable) mold, which is made of a pattern (which can also be very expensive).

Any castings with internal channels also require the use of cores; additional costs. Again, these are disposable items, and it is likely that you will need more than one for each casting.

All-metal faucets cost more because they...more costly; in terms of materials and labor.

Gasketless faucets usually have a plastic disc with a rubber seat, most of which are spring-loaded, but not all. The last part is the pivot, which is usually also plastic in metal and plastic faucets. Rubber is the failed part, which is the same in plastic and metal frame faucets. The seats are easy to change, and many seats are color-coded according to size. Except for hard water sediments, I didn't see much difference. With hard water, plastic frames are more likely to break than metal frames.

Whether it is a Plastic Kitchen Faucet or a Plastic Kitchen Faucet, they are in the same condition, so whether it is metal that is easier to break or plastic is easier to break, they can be selected.