Kenyan local banks are not safe, especially Equity Bank. Equity employees can remove your money at any time as they wish. Even the scams you see in Safaricom are employee-driven. The problem is the society, not necessarily the leadership. If you have rotten people, it doesn't matter where you put them. Watchmen collude to steal; House helps, bank employees, and government employees, etc.
If you put money in a mattress, now that is when one day those near you will take you for cleaners, especially family or close friends. Most of my dough stays in volatile US stocks, but I move them every day, if not attracting more money!