Why extra call to API for getUser()?

Method `getUser()` in TelegramDriver issue `getChatMember` telegram API call. Why fire 'expensive' by time API call while Telegram provides `from` entry in each call which is enought in most cases?

"from": {
"id": 000000,
"is_bot": false,
"first_name": "fname",
"last_name": "lname",
"username": "username",
"language_code": "en"
},

I think it must extract that information and may be implement in `BotMan\Drivers\Telegram\Extensions\User` getters for additional data, provided by `getChatMember` and call API only if one of additional fields is requested