You can expend ENORMOUS amounts of resources on cascaded gas centrifuges to separate the U235 from U238, or ENORMOUS amounts of resources in research, engineering, and precision machining a P239 implosion device. Why do both?
U235 is much easier to produce than plutonium.
There is a reason that China’s first bomb, South America’s bomb, India’s bomb, and Pakistan’s bomb were EU.
The primary benefit of a P239 bomb is they can be much smaller and boosted with fusion. If you goal is to blow up a city, you don’t need tactical weapons, just strategic.
Hence, why counties that have need for tactical nukes (e.g., US, Israel (shh!), England, and Russia) are the P239 business.
The arabs just want to nuke whole cities.