They are incompetent as hell. They can't even replace older G-3s with new light weight variants.
CZ deal was good but they decided not to.
They just need VT-4 and stuff even if infantrymen have to carry a musket or flintlock gun.
Signing a contract for a few hundred fighter jets and tanks is much easier than a rifle.
With the rifle replacement, we're talking about potentially millions, with hundreds of thousands of soldiers that need to be retrained to use the new rifles. You also need to set up manufacturing facilities for the rifles and the ammunition, among a vast number of other things you need to do. Once all of this is accomplished, you have to spend a good decade to replace the existing stockpile of rifles. It took Israel literally 10 years to replace the regular infantry's old rifles with the Tavor, and that's not even counting reserve units, special forces...etc.
With tanks and fighters, you can buy them off the shelf, sign a few maintenance contracts with a trusted arms dealer, and still be fine. With rifles, it's much more complicated and time consuming.
The rifle is the life blood of the army. Even when the tanks are destroyed, even when the fighter jets are all shot down, the rifle can still be enough to fight back. Israel learned that lesson the hard way, when they went into Labanon, the US learned this in Afghanistan and Iraq.
Making a bad purchase of a rifle can be the biggest disaster to occur to an army, the UK learned this against the argentinians during the Falkland wars, where the UK had tech superiority, but their shittier single shot FALs were completely outclassed by the Argentinian FALs, to the point that the British soldiers literally started taking and using the rifles they got from dead Argentinian soldiers.
When the US invaded Afghanistan and later Iraq, US soldiers did the same, as their M-16/M-4s kept jamming due to the rough dusty environment, being forced to grab a back up AK rifle off of the bodies of militants.
During the height of militancy in Pakistan, Pakistani special forces literally had to switch from their m-4s and f-2000s to the Type-56s and similar AKs, because of similar problem that the US faced. The environment in places like Swat and Waziristan was too rough, and the heavily wooded areas were especially rough, as their 5.56 NATO rounds couldn't penetrate the thick trees, and the muddy environment kept jamming their weapons. They had to switch to the AK type rifles like the type-56, with its larger round to compensate for this problem.
Thankfully, a lot of modern rifles have compensated for this problem, so it's not as big of a deal. Still 1 put of a thousand verses 1 out of 10,000 rifles jamming can mean the life and death of a soldier, it can even make an entire battle unwinnable, leading to a large amount of deaths.
Tl;dr it's not incompetence, it's just difficult.