Absolutely true.

"Fortunately having an unchallenging job can provide lots of time and energy for research and side projects that can lead to jumping into more interesting work."

You know, in theory this is true. In practice, I've been in this situation a couple of times in my career. And it sucked. Hard. It was soul crushing. It was depressing. I found myself emotionally drained at the end of every day. I would complete my work in a short timespan every morning, then somehow end up mindlessly cruising Facebook (or whatever passed for Facebook back then) throughout the day. My latent productivity plummeted in direct correlation to my plummeting mental engagement.

Maybe I'm an unusual case. But oddly enough, I find a boring, trivial, meaningless job almost more draining than a challenging and extremely fast-paced one. In the latter, at least I am revved up, and thus I have energy for side projects on the weekends.

That's not always true.

It only works if the job is both easy and coming at a low enough pace that you can do it in a couple of hours and forget about it.

However, when the amount of work itself is overwhelming and the job is unchallenging, it works out the other way: it sweeps all your energy and leaves you burnt out at the end of the day. You get home and all you want to do is drink a couple of beers and watch a TV series until you're sleepy enough that you can go to bed and fall asleep, getting just enough sleep to be ready for more bullshit the next day.

I'm on some twisted variant of that where I'm stuck trying to sift through a backlog of tutorials or Algorithm review so I can still be considered remotely competent enough to apply elsewhere, finding myself staying up 'til 1, sometimes 2AM, only to wake up the next day to repeat the cycle. Only reason I haven't 'rocked the boat' yet with my supervisor is because it's a fairly high-profile project, but definitely starting to apply elsewhere if they ignore my request to switch from backend to front-end after this. Glad to know I'm not the only one.

That is a sign that either your employer needs more qualified people or you need another job.

I completely get where you are coming from though, hah!

I'm in a similar boat. Not as bad as your experience sounds, but I would definitely consider it an unchallenging job that leaves me feeling more stressed than anything. I have lots of ideas I want to pursue in my free time, but I know that if I get involved in a project it will make time go by quicker and I'll just have to be back at work sooner. Everything I do in my off time is designed to make it feel as long as possible. I haven't read a book in months. Sometimes I don't even want to watch TV because it's too entertaining.

God damn that's depressing to write down.

If not, I recommend "Timeline" by Michael Crichton. It's not a taxing or immensely intellectual read, but it's a great adventure story with very interesting and suspenseful parts. It's a lot of fun to read and definitely won't feel like work - it'll feel like play.

I won't lie though, the ego-hit of being "the dumb one" when surrounded by truly brilliant people is hard - 100% worth it - but hard.

I know that I am good at what I do but I keep being curious and waiting to be told "You're wrong. this is the better way of doing it". That's definitely worth multiple cuts to your ego.

Corollary: every non-empty room has at least one person that is wrongly there.