Uh, how do you plan to use dumb bombs like that in a conflict like Ukraine?
That would require you to be able to fly right over the enemy airfield, they'd need to have no air defenses whatsoever.
You'll damage a runway at the cost of a pilot (probably $5M+), aircraft (at least $10M), and dumb bombs ($30k each). Putting your total price paid for thousands of dollars worth of runway damage in the tens of millions.
> when a high intensity conflict with a real military power begins you can be sure most of your airports will be targets, which is exactly what happened to Ukraine, not even 2 weeks in the conflict
That kind of damage is fixed within hours at a cost of low thousands of dollars at most. Russia can do only it using incredibly expensive standoff-range missiles, spending at the very least hundreds of thousands if not millions to punch a hole on a runway that takes a few hours to repair.