One of the big changes has been the shift to (mostly) solid-state lasers for this kind of work - it's taken longer to scale those up to weaponized power levels, but they're much easier to work with and miniaturize. The telecoms industry did a lot of the fundamental work in this area for fiber optics purposes. Back in the 70s they were using mostly chemical-powered lasers, which could get high powers without high-performance electrical power sources, but were a
pain to work with (hence the use of large airliners).
Aircraft these days have much better electrical power systems (since all control surfaces and a lot more engine operation is electrically powered), and new aircraft carriers and surface combatants are being designed with about 50-100% margin on electrical power to make them compatible with these systems in the future.