If you've been looking at over-ear headphones, you may notice that battery life is far better with those than wireless earbuds. It's simply down to size. Over-ear headphones are weightier and larger meaning there's more room for a powerful battery.
Earbuds are small and therefore their battery is smaller too. They heavily rely on their charging cases to ensure you won't run out of power while on the move, but that's not always convenient if you need to use them at the same time.
Fortunately, earbud battery life is improving steadily so the majority of users will be able to use them even on long journeys without needing to recharge as often as in the past.