Not really! Chinese grammar seems easy for simple communication.
If you want to reach the professional level, the grammar would not be “so easy”. Further, complexity of grammar is just one aspect of the language. There are numerous other issues that make Mandarin learning difficult to the foreigners.
A few examples.
Characters: there are thousands of Chinese characters. Although 2,000 characters are good enough for foreign students learning Chinese, for professional levels, it’s certainly over 3,000.
Tones: Tons make the situation more complicated. The characters like 吗, 马, 嘛, and 妈 all sound Ma without tone. However, with tones, these characters have very different meanings. 么 is another way to say 吗.
Similar looking characters: look at these characters: 头, 实, 买, 卖, 续. These characters can be confusing to many out there. Further, 买 and 卖 are both “Mai” without tones. When you add tone, one is to buy (买, Mǎi), another is to sell (卖, Mài). Tones just can’t be ignored.
Chinese idioms – there are thousands of Chinese idioms. These idioms have been derived from historical events (For example: 四面楚歌). You need to know Chinese idiom stories to appreciate the real meaning of the idioms.
Thankfully, a sincere practice and choosing correct study material will go a long way to help you learn Chinese. It takes a bit time, but it’s not impossible.