The SDB is a typical US answer to a self-inflicted problem. You can't fit weapons as large (especially as long) as you used to be able to carry on the internal weapon bays of the multi-role stealth fighters. So they had to make the bombs physically smaller. This in turn meant the warhead was smaller so to achieve the same terminal effect the bomb has to be a lot more accurate. The problem is each of the SDBs, especially the SDB-II, costs as much as a top luxury or sports car. Then they use these bombs on technicals or guys on a motorcycle.
Not at all.
The SDB and SDB II can be of course loaded on any aircraft compatible with them, not only stealth fighters.
4th gen fighters, cold war era bombers, stealth bombers, future stealth bombers in development -- each of those platforms with suitable software and datalinks and structural compatibility has the potential to carry these weapons, and the larger the aircraft, the larger the payload, and the larger the payload the greater the number of weapons.
And with weapons like SDB II, they are not only satellite guided but also semi active laser homing and even imaging infrared and millimeter wave radar guidance of their own, meaning they're extremely difficult to jam and are able to identify and hit their own targets (including moving targets).
And all this in a weapon which is shaped specifically to be able to penetrate hardened aircraft shelters, with a range of 100+ km.
A single stealth bomber loaded with SDB IIs would probably be able to destroy a single air base and all of its individual parked aircraft (either in hardened bases or out in the open) in a single sortie.
And it goes without saying what benefits this strike weapon provides to 4+ gen strike fighters and 5th gen fighters -- the ability to hit targets at 100+km with a large magazine load with extreme precision is a massive expansion in capability compared to the previous smallest PGM size they had being 250kg in weight with a range of only 25-60km at best.
I wouldn't be surprised if powered variants of SDB II emerge to extend its range and flexibility (similar to SPEAR 3), and with enhanced datalinking capabilities so a single aircraft can drop anywhere from 16 to 100+ SDB IIs in one load (depending on the size of the aircraft) and the weapons are all themselves able to allocate targets between themselves.
I wouldnt' be surprised if jamming/EW variants of SDB II also emerge, again similar to SPEAR 3.
I suppose what I'm saying is that having smaller weapons which with very good guidance is desirable if you have the money for it, because it allows a single aircraft performing a single sortie to prosecute more targets in said sortie.
The effects on your aircraft's efficiency and freeing up the rest of your aircraft to do other things cannot be understated.
