I mentioned that first because it's easy to fall into a lifestyle trap and think the only way to cope is to get a job that makes more. The formula for money is income minus expenses, so you always have two variables you can play with.
It also makes a nice mental segue for people into the topic of getting a new job, a topic which people can be adverse to. It creates a choice that seemingly wasn't there before.
FWIW I wouldn't be so quick to turn your nose up at side gigs.
I have a friend who picked up an old vinyl decal cutter and now makes a significant amount of his income by selling custom decal stickers for cars and windows and such to local businesses.
Similarly my neighbor does lawn aerating in the spring and sprinkler blowouts in the fall and considers it a refreshing break from his work as a PM.
>If you want more money look at where you can save money (not eating out, buying generic products, etc.) and things you might be able to do on the side to earn more.
Oh dear god, the guy is depressed and now he has to stop buying his daily coffee too? And possibly a second job!?? You're an engineer, not a tollbooth operator. You're in one of the few fields that's actually growing and still pays worth a shit.
On the money front, take several queues from Ramit Sethi. Level up, do a cool side project with the latest React/Vue/Node and learn a bit about selling yourself.
Most engineers, even if they're really good, decide to take the humble, quiet route and demand a "fair pay". It's bullshit, it's a cop out, and if you're just 10% confident, you can increase your next jobs's salary with the money the other introverted engineers left on the table for you.