What could be the reason for Visa refusal below? [closed]

I hold a Namibian passport and work as a customer service representative. I recently applied for an Estonian national work visa to work as a food server. I attached supporting documents such as an Estonia work permit, a bank statement, travel insurance, a letter from Estonia employer

In addition to the mandatory documents on my visa application, I attached a cover letter in which I stated that my intention is to work in Estonia in order to obtain sufficient funds to finance my established businesses in Namibia, and I attached registration certificates as proof, but unfortunately, I received a refusal letter with reasons below.

(1-there are reasonable doubts regarding your intention to leave the territory of the Republic of Estonia before the expiry of the visa;

(2-you have not justified the purpose and conditions of the intended stay;

there are reasonable doubts regarding the reliability of the statements you made about the purpose of your stay in the territory of the Republic of Estonia due to the evidence that is available to the authority or due to objective circumstances indicating that the purpose of the stay could be different than declared;