Technology

It's the same issue with cotton; it takes a lot of water and land. With this, one can feasibly use less land for more product; as well as avoiding child and slave labour which has been associated with cotton production in countries with lax or non-existent labour laws.

In short: Efficiency and ethics.

It probably has to do with difficulty of cultivation. Meat is a real pain to grow in the lab, the methods are already pretty complex and production is still low. At the end of the day it's adapted to be in an animal. On the other hand, cotton is just pure cellulose, which any number of organisms can produce including bacteria.

Mandatory mention that I didn't read the article.

Others note the land and water use issue vut it seems there are a lot of other crops that would be bigger targets on those fronts.

It's very likely other teams are working on other crops, and this just happens to be a high profile early success.

Not just land and water use, but there may be market reasons, as well as reasons relating to consistency and application specific variations, too.

A bad grow season means lowered supply, higher global cotton prices, etc. Natural farming means lots of supply at harvest, money spent on storage and dwindling supply during the off seasons. There’s often transport costs (usually), and there’s always cleaning and deseeding, too.

On the environment front, while polyester and other plastic-based fibers have their uses, they are often used instead of cotton due to cost. Consumers are becoming more aware of micro plastics, and may start changing buying habits as a result. It’s also possible that governments may start to regulate artificial fibers, too.

Technology-wise, it may be possible to tweak the fibers for specific use cases. It may even be possible to grow colored fibers, or fibers with enhanced strength.

A lab-grown option, especially if at scale, can mean a constant supply of fibers near looms that are customizable, need less post-processing, and are more appealing to consumers.

This is quite a bit easier to accomplish than meat (as a product people want to consume). This is genetically modified yeast that produces cotton fibers. The same thing is done to produce insulin, and many other products.

Meat is far more complex though. It's not super difficult to grow meat, but it is in a form that resembles meat people expect and want. You can't just grow muscle. You need to have the correct ratio of fats, and not just the correct ratio, but it should be in the meat in an expected way, not just a seperate layer on top. It's complicated. It will be a huge benefit when it's available, but there are probably dozens of companies already working on it.