Some scientists argue that the properties of caffeine are somewhat exaggerated. For example, there is even more of it in green tea, but there is almost no invigorating effect from green tea. They say it's a bunch of substances, not caffeine itself.
I would recommend you to choose tea on a different basis: it is good tea or donkey urine. In the second case, you will even harm yourself. And forget the word "caffeine" ... Do not fool yourself. This is a very abstract concept ...
I don't know about the beneficial properties, but there is a special evening tea. It's just caffeine-free. Ahmad tea definitely has such tea bags, it is even cheaper than regular black tea. The taste is no different, perhaps less intense.