If that is the case, why not just load the lasers on something like a C-130? Lots of room, load carrying capacity. Four engines to generate power for the laser(s), proven design... Fly in slow and non-stealthy, but so what. Make a statement, “I own this airspace and there’s nothing you can do about it, come up and try me and my friends.”
This is why there will be a place for C-130 type planes with lasers, but only for shooting down ballistic missiles at their boost phase (with those ballistic missiles belonging to the likes of North Korea and Pakistan). But against true near-peer adversaries, like Russia and China, the USAF/USN will use advanced fighters armed with lasers. This will to avoid the circumstances that led to the U-2 getting shot down. Reliance on only ONE advantage, which in the case of the U-2 was very high flight altitude ...which worked until the Soviets got tired of being photographed with impunity, and developed a missile that could reach out to the altitudes that the U-2 used to fly with impunity previously. Compare the U-2 with the SR-71 for example ...the Blackbird can fly super high as well, but is also super fast (and by some measures, kind of stealthy). Those are layered advantages, and that approach works. Same reason why the F-22 has a high degree of stealth, can fly high, can fly fast (and super cruise), has extremely maneuverability, has an advanced radar that is hard to detect, etc. Why? Layered advantages, meaning that even if one is defeated the others are more than enough to maintain dominance.
The C-130 would have only one real advantage - the ability to smite down ALMOST anything coming at it - and that would work until, like the U-2s invincibility against SAMs, it didn't.
To be truly invincible it requires both invincibility through potence, as well as invincibility through invisibility. Leopards are powerful jungle cats, blessed of tooth and claw, but they still have great camouflage and creep up on their prey like silent shadows.
The C-130 would die over China. Not at first, but eventually it would.