npnpnp

A lot of other comments have covered other aspects, and here's another one. If balloons become commonplace, I'd bet that they don't scramble the latest and greatest to shoot them down. It could probably be done with a turboprop.

The F-22 was probably used in the most popular case as a show of force.

But remember - these planes are often up in the air anyway for training. The US Air Force has some of the highest flight hours per pilot of any air forces. Yes it will cost more, but it's hard to say by how much.

Fighter jets don't just sit in hangars all day. They're no good without trained pilots.

They're probably being targeted before getting in range of media cameras, and are likely classified until declassified. I would doubt if we see another one over populated areas anytime soon. I would also bet these start getting shot down as they enter the ADIZ.

It depends. SRBs are pretty simple (yet still incredibly hard to make remotely safe).

Orbital rocket engines are not “point up and ignite fuel.” You’re right, they don’t need air intakes - they need cryogenic liquid oxygen and all the support equipment involved in using it! Jet engines have it easy being able to harvest the oxidizer as they fly.

There are many, many, points of failure in modern rockets . You could argue that jet engines were the precursor to modern turbo pump design.

edit It’s also worth noting that the turbopump environment is dramatically more hostile in rockets. LOX is really nasty stuff at those temperatures and pressures.

By that logic, scramjets are the simplest of all!

But really, there’s an order of magnitude more engineering that goes into so many facets of rockets and rocket engines. On paper they’re similar, but the stresses and constraints are much, much higher.