Many people can, they just choose to spend that discretionary income on other non-essentials instead, like daily $4 cups of coffee, $2 energy drinks, new phones and flat screen TVs every year, nights out at the movies, etc etc., that don't seem like much each time, but add up just the same. It's all about priorities.
Had a coworker make a smart remark at lunch one time about “ how much the rest of us at the table spent on guns & ammo monthly.”
He said that while sitting there with the newest iPhone and an Apple Watch and he drives a newer Escalade.
Me ? $150 smart phone, & 2003 Grand Marquis ( just over 100k miles ) & F100.
I called him on it, and his $10 a day Starbucks habit, he quickly understood if ‘it’s your thing‘ you will find a way.