You're saying no one capitalizes software development costs anymore? The rest of the internet disagrees strongly. The finance team at my employer would disagree strongly. Accountants talk to dev teams all the time about how many hours went into new development vs maintenance. It's not just a temporary IRS rule. It's GAAP.

It's the same in other industries. In your example, if labor went into building a whole new assembly line that pays itself off over several years, capex. If it just goes into building products to sell, opex.

https://www.hibob.com/blog/r-and-d-capitalization/