Experience traveling with a 6 month old, any advice?

We want to take our newborn to see her grandmother, who due the medical reasons cannot travel.

My wife says I'm being overly considerate. But that's because for most of my life I've thought, "keep your f****** kid at home. Don't bring that piece of s*** to the movies, why the f*** would you bring a crying baby onto a plane", etc.

I've looked into trains and even buses, and I can't justify spending three times more on a bus ticket than a plane flight, or 6 times more for a slow arse train.

I'm trying to convince the wife to drive instead, But it's across country and would take a few days each way....which may be considerate to others, is "inconsiderate to her and the baby"

Is flying with a 6-month-old, 5 hours each way, that bad? I assume that the air pressure will cause her to cry and I'll spend the entire time feeling like a piece of shite for being the inconsiderate piece of trash that says "tolerate me"

Any advice on flying with a baby. Would puddle jumping be better (short flights) as in long distance will cause her to be restless vs giving her a break every 90 mins or so.